Navigation: rename "Contribute" to "Community"

* move "Source" from "Community" to "Download"
* move "Support" from "Documentation" to "Community"
* fix headlines in N&N
diff --git a/noteworthy/2.1/index.php b/noteworthy/2.1/index.php
index 7c18111..17bbc6b 100644
--- a/noteworthy/2.1/index.php
+++ b/noteworthy/2.1/index.php
@@ -22,7 +22,7 @@
 
 <div id="midcolumn">
 
-  <h1><?php echo $title ?></h1>
+  <h1><?= $PAGE_TITLE ?></h1>
 
   <p>
     Here's a list of the most noteworthy things in the RAP