Site plugin updates, fluido 1.9, small docs update.

Bump m-site-p to 3.9.1 and m-project-info-plugin to 3.1.1
diff --git a/pom.xml b/pom.xml
index 5e8aaf7..2e9ba4b 100644
--- a/pom.xml
+++ b/pom.xml
@@ -208,6 +208,17 @@
             <helpPackageName>org.apache.maven.plugins.help</helpPackageName>
           </configuration>
         </plugin>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-site-plugin</artifactId>
+          <version>3.9.1</version>
+        </plugin>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-project-info-reports-plugin</artifactId>
+          <version>3.1.1</version>
+        </plugin>
+
       </plugins>
     </pluginManagement>
     <plugins>
diff --git a/src/site/apt/index.apt.vm b/src/site/apt/index.apt.vm
index d3909d1..c1d9499 100644
--- a/src/site/apt/index.apt.vm
+++ b/src/site/apt/index.apt.vm
@@ -68,12 +68,10 @@
 * Usage
 
   General instructions on how to use the Help Plugin can be found on the {{{./usage.html}usage page}}. Some more
-  specific use cases are described in the examples given below. Last but not least, users occasionally contribute
-  additional examples, tips or errata to the
-  {{{http://docs.codehaus.org/display/MAVENUSER/Help+Plugin}plugin's wiki page}}.
+  specific use cases are described in the examples given below.
 
-  In case you still have questions regarding the plugin's usage, please have a look at the {{{./faq.html}FAQ}} and feel
-  free to contact the {{{./mailing-lists.html}user mailing list}}. The posts to the mailing list are archived and could
+  In case you still have questions regarding the plugin's usage, please feel free to contact the
+  {{{./mailing-lists.html}user mailing list}}. The posts to the mailing list are archived and could
   already contain the answer to your question as part of an older thread. Hence, it is also worth browsing/searching
   the {{{./mailing-lists.html}mail archive}}.
 
@@ -83,7 +81,7 @@
   entire debug logs, POMs or most preferably little demo projects attached to the issue are very much appreciated.
   Of course, patches are welcome, too. Contributors can check out the project from our
   {{{./scm.html}source repository}} and will find supplementary information in the
-  {{{http://maven.apache.org/guides/development/guide-helping.html}guide to helping with Maven}}.
+  {{{https://maven.apache.org/guides/development/guide-helping.html}guide to helping with Maven}}.
 
 * Examples
 
diff --git a/src/site/site.xml b/src/site/site.xml
index 33f1166..d210372 100644
--- a/src/site/site.xml
+++ b/src/site/site.xml
@@ -19,9 +19,13 @@
 under the License.
 -->
 
-<project xmlns="http://maven.apache.org/DECORATION/1.0.0"
-  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-  xsi:schemaLocation="http://maven.apache.org/DECORATION/1.0.0 http://maven.apache.org/xsd/decoration-1.0.0.xsd">
+<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 https://maven.apache.org/xsd/decoration-1.8.0.xsd">
+  <skin>
+    <groupId>org.apache.maven.skins</groupId>
+    <artifactId>maven-fluido-skin</artifactId>
+    <version>1.9</version>
+  </skin>
   <body>
     <menu name="Overview">
       <item name="Introduction" href="index.html"/>
@@ -29,7 +33,7 @@
       <item name="Usage" href="usage.html"/>
       <item name="FAQ" href="faq.html"/>
       <!-- According to https://issues.apache.org/jira/browse/MNGSITE-152 -->
-      <item name="License" href="http://www.apache.org/licenses/"/>
+      <item name="License" href="https://www.apache.org/licenses/"/>
       <item name="Download" href="download.html"/>
     </menu>
     <menu name="Examples">