add help target, which points to -projecthelp


git-svn-id: https://svn.apache.org/repos/asf/httpd/docs-build/trunk@333070 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/build.xml b/build.xml
index 2f7dfd4..d1301e6 100644
--- a/build.xml
+++ b/build.xml
@@ -43,6 +43,14 @@
     <path><pathelement path="..${file.separator}" /></path>
 </pathconvert>
 
+
+<!-- help                                                                 -->
+<!-- ==================================================================== -->
+<target name="help" description="- use `build -projecthelp` instead!">
+    <echo message="Try `build -projecthelp`" />
+</target>
+
+
 <!-- typemaps                                                             -->
 <!-- ==================================================================== -->
 <target name="typemaps" depends="metafiles" unless="typemaps.done"