[MPOM-223] prepare site for extensions parent POM
diff --git a/doxia-tools/site-pom.xml b/doxia-tools/site-pom.xml
index 65f8984..373ce37 100644
--- a/doxia-tools/site-pom.xml
+++ b/doxia-tools/site-pom.xml
@@ -25,7 +25,7 @@
   <parent>
     <groupId>org.apache.maven</groupId>
     <artifactId>maven-parent.</artifactId>
-    <version>33</version>
+    <version>34-SNAPSHOT</version>
     <relativePath>../site-pom.xml</relativePath>
   </parent>
 
diff --git a/doxia-tools/src/site-docs/site.xml b/doxia-tools/src/site-docs/site.xml
index fd48854..85bb8a1 100644
--- a/doxia-tools/src/site-docs/site.xml
+++ b/doxia-tools/src/site-docs/site.xml
@@ -32,6 +32,7 @@
       <item name="Maven" href="../index.html"/>
       <item name="Archetypes" href="../maven-archetypes-bundles/index.html"/>
       <item name="Plugins" href="../maven-plugins/index.html"/>
+      <item name="Extensions" href="../maven-extensions/index.html"/>
       <item name="Shared Components" href="../maven-shared-components/index.html"/>
       <item name="Skins" href="../maven-skins/index.html"/>
       <item name="Doxia Tools" href="../doxia-tools/index.html"/>
diff --git a/maven-extensions/site-pom.xml b/maven-extensions/site-pom.xml
index 98dea5e..bfcf17d 100644
--- a/maven-extensions/site-pom.xml
+++ b/maven-extensions/site-pom.xml
@@ -26,7 +26,7 @@
   <parent>
     <groupId>org.apache.maven</groupId>
     <artifactId>maven-parent.</artifactId>
-    <version>33</version>
+    <version>34-SNAPSHOT</version>
     <relativePath>../site-pom.xml</relativePath>
   </parent>
 
diff --git a/maven-extensions/src/site-docs/apt/index.apt.vm b/maven-extensions/src/site-docs/apt/index.apt.vm
new file mode 100644
index 0000000..acc3c7b
--- /dev/null
+++ b/maven-extensions/src/site-docs/apt/index.apt.vm
@@ -0,0 +1,72 @@
+ -----
+ Introduction
+ -----
+ Hervé Boutemy
+ -----
+ 2020-01-16
+ -----
+
+~~ Licensed to the Apache Software Foundation (ASF) under one
+~~ or more contributor license agreements.  See the NOTICE file
+~~ distributed with this work for additional information
+~~ regarding copyright ownership.  The ASF licenses this file
+~~ to you under the Apache License, Version 2.0 (the
+~~ "License"); you may not use this file except in compliance
+~~ with the License.  You may obtain a copy of the License at
+~~
+~~   http://www.apache.org/licenses/LICENSE-2.0
+~~
+~~ Unless required by applicable law or agreed to in writing,
+~~ software distributed under the License is distributed on an
+~~ "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+~~ KIND, either express or implied.  See the License for the
+~~ specific language governing permissions and limitations
+~~ under the License.
+
+~~ NOTE: For help with the syntax of this file, see:
+~~ https://maven.apache.org/doxia/references/apt-format.html
+
+${project.name}
+
+    This POM is the common parent of all of the {{{/extensions/}Maven extensions}}
+    in the Apache Maven project.
+
+* The <<<run-its>>> Profile
+
+    This POM provides <<<run-its>>> profile for running Integration Tests to check real extension execution.
+    A default configuration for <<<maven-invoker-plugin>>> is defined, that every extension needs to enhance
+    to match its prerequisite. Then ITs are launched in every extension with following command:
+
++---+
+mvn -Prun-its verify
++---+
+
+
+* Site Publication
+
+    Since Maven extensions are always mono-module builds, this parent POM has configured <<<maven-scm-publish-plugin>>>
+    {{{/plugins/maven-scm-publish-plugin/examples/one-module-configuration.html}mono module optimization}}
+    to ease site build & deployment in only one integrated and simplified command:
+
++-----+
+mvn -Preporting site-deploy
++-----+
+
+* History
+
+#if( $project.version.endsWith( "SNAPSHOT" ) )
+#**##set( $prev = 33 )
+  master: {{{https://github.com/apache/maven-parent/tree/master/maven-extensions/pom.xml}$project.version}}
+  ({{{https://gitbox.apache.org/repos/asf?p=maven-parent.git;a=blobdiff;f=maven-extensions/pom.xml;hb=master;hpb=maven-parent-$prev}diff}})
+#end
+#macro ( display $version $date )
+#**##set( $prev = $version - 1 )
+|  {{{https://github.com/apache/maven-parent/tree/maven-parent-$version/maven-extensions/pom.xml}$version}}
+| ({{{https://gitbox.apache.org/repos/asf?p=maven-parent.git;a=blobdiff;f=maven-extensions/pom.xml;hb=maven-parent-$version;hpb=maven-parent-$prev}diff}}) | $date |
+#end
+
+*--------------+------------+
+|| <<Version>> || <<Release Date>> ||
+*--------------+------------+
+#display( 34, '2020-01-17' )
+*--------------+------------+
diff --git a/maven-extensions/src/site-docs/site.xml b/maven-extensions/src/site-docs/site.xml
new file mode 100644
index 0000000..a16931e
--- /dev/null
+++ b/maven-extensions/src/site-docs/site.xml
@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+<project xmlns="http://maven.apache.org/DECORATION/1.8.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/DECORATION/1.8.0 http://maven.apache.org/xsd/decoration-1.8.0.xsd">
+
+  <body>
+    <breadcrumbs>
+      <item name="Maven" href="https://maven.apache.org/pom/maven/index.html" />
+      <item name="Extensions" href="https://maven.apache.org/pom/maven/maven-extensions/index.html" />
+    </breadcrumbs>
+
+    <menu name="Maven Parent POMs">
+      <item name="Maven" href="../index.html"/>
+      <item name="Archetypes" href="../maven-archetypes-bundles/index.html"/>
+      <item name="Plugins" href="../maven-plugins/index.html"/>
+      <item name="Extensions" href="../maven-extensions/index.html"/>
+      <item name="Shared Components" href="../maven-shared-components/index.html"/>
+      <item name="Skins" href="../maven-skins/index.html"/>
+      <item name="Doxia Tools" href="../doxia-tools/index.html"/>
+    </menu>
+
+    <menu ref="parent" />
+  </body>
+</project>
\ No newline at end of file
diff --git a/maven-plugins/site-pom.xml b/maven-plugins/site-pom.xml
index 61d52cf..49122f3 100644
--- a/maven-plugins/site-pom.xml
+++ b/maven-plugins/site-pom.xml
@@ -26,7 +26,7 @@
   <parent>
     <groupId>org.apache.maven</groupId>
     <artifactId>maven-parent.</artifactId>
-    <version>33</version>
+    <version>34-SNAPSHOT</version>
     <relativePath>../site-pom.xml</relativePath>
   </parent>
 
diff --git a/maven-plugins/src/site-docs/site.xml b/maven-plugins/src/site-docs/site.xml
index a7c5bba..e7e92fa 100644
--- a/maven-plugins/src/site-docs/site.xml
+++ b/maven-plugins/src/site-docs/site.xml
@@ -25,13 +25,14 @@
   <body>
     <breadcrumbs>
       <item name="Maven" href="https://maven.apache.org/pom/maven/index.html" />
-      <item name="Plugins" href="https://maven.apache.org/pom/maven/maven-plugin/index.html" />
+      <item name="Plugins" href="https://maven.apache.org/pom/maven/maven-plugins/index.html" />
     </breadcrumbs>
 
     <menu name="Maven Parent POMs">
       <item name="Maven" href="../index.html"/>
       <item name="Archetypes" href="../maven-archetypes-bundles/index.html"/>
       <item name="Plugins" href="../maven-plugins/index.html"/>
+      <item name="Extensions" href="../maven-extensions/index.html"/>
       <item name="Shared Components" href="../maven-shared-components/index.html"/>
       <item name="Skins" href="../maven-skins/index.html"/>
       <item name="Doxia Tools" href="../doxia-tools/index.html"/>
diff --git a/maven-shared-components/site-pom.xml b/maven-shared-components/site-pom.xml
index 5271702..effc586 100644
--- a/maven-shared-components/site-pom.xml
+++ b/maven-shared-components/site-pom.xml
@@ -26,7 +26,7 @@
   <parent>
     <groupId>org.apache.maven</groupId>
     <artifactId>maven-parent.</artifactId>
-    <version>33</version>
+    <version>34-SNAPSHOT</version>
     <relativePath>../site-pom.xml</relativePath>
   </parent>
 
diff --git a/maven-shared-components/src/site-docs/site.xml b/maven-shared-components/src/site-docs/site.xml
index 77e84ae..0f89840 100644
--- a/maven-shared-components/src/site-docs/site.xml
+++ b/maven-shared-components/src/site-docs/site.xml
@@ -32,6 +32,7 @@
       <item name="Maven" href="../index.html"/>
       <item name="Archetypes" href="../maven-archetypes-bundles/index.html"/>
       <item name="Plugins" href="../maven-plugins/index.html"/>
+      <item name="Extensions" href="../maven-extensions/index.html"/>
       <item name="Shared Components" href="../maven-shared-components/index.html"/>
       <item name="Skins" href="../maven-skins/index.html"/>
       <item name="Doxia Tools" href="../doxia-tools/index.html"/>
diff --git a/maven-skins/site-pom.xml b/maven-skins/site-pom.xml
index ae1091e..ce7a528 100644
--- a/maven-skins/site-pom.xml
+++ b/maven-skins/site-pom.xml
@@ -26,7 +26,7 @@
   <parent>
     <groupId>org.apache.maven</groupId>
     <artifactId>maven-parent.</artifactId>
-    <version>33</version>
+    <version>34-SNAPSHOT</version>
     <relativePath>../site-pom.xml</relativePath>
   </parent>
 
diff --git a/maven-skins/src/site-docs/site.xml b/maven-skins/src/site-docs/site.xml
index e050269..957f714 100644
--- a/maven-skins/src/site-docs/site.xml
+++ b/maven-skins/src/site-docs/site.xml
@@ -32,6 +32,7 @@
       <item name="Maven" href="../index.html"/>
       <item name="Archetypes" href="../maven-archetypes-bundles/index.html"/>
       <item name="Plugins" href="../maven-plugins/index.html"/>
+      <item name="Extensions" href="../maven-extensions/index.html"/>
       <item name="Shared Components" href="../maven-shared-components/index.html"/>
       <item name="Skins" href="../maven-skins/index.html"/>
       <item name="Doxia Tools" href="../doxia-tools/index.html"/>
diff --git a/site-pom.xml b/site-pom.xml
index 818242e..705eeab 100644
--- a/site-pom.xml
+++ b/site-pom.xml
@@ -25,7 +25,7 @@
   <parent>
     <groupId>org.apache.maven</groupId>
     <artifactId>maven-parent</artifactId>
-    <version>33</version>
+    <version>34-SNAPSHOT</version>
     <relativePath>./pom.xml</relativePath>
   </parent>
 
@@ -37,6 +37,7 @@
   <url>https://maven.apache.org/pom/maven/</url>
 
   <modules>
+    <module>maven-extensions/site-pom.xml</module>
     <module>maven-plugins/site-pom.xml</module>
     <module>maven-shared-components/site-pom.xml</module>
     <module>maven-skins/site-pom.xml</module>
diff --git a/src/site-docs/site.xml b/src/site-docs/site.xml
index 779a9ed..f8b0ab5 100644
--- a/src/site-docs/site.xml
+++ b/src/site-docs/site.xml
@@ -79,6 +79,7 @@
     <menu name="Maven Parent POMs">
       <item name="Maven" href="index.html"/>
       <item name="Plugins" href="maven-plugins/index.html"/>
+      <item name="Extensions" href="maven-extensions/index.html"/>
       <item name="Shared Components" href="maven-shared-components/index.html"/>
       <item name="Skins" href="maven-skins/index.html"/>
       <item name="Doxia Tools" href="doxia-tools/index.html"/>