Documentation update

Change-Id: Ice12ade748f152da7b614433f2e24072071fa997
diff --git a/pom.xml b/pom.xml
index 97b349d..39e9f48 100644
--- a/pom.xml
+++ b/pom.xml
@@ -59,7 +59,7 @@
               <Implementation-Title>Manifest Subscription plugin
               </Implementation-Title>
               <Implementation-Vendor>AMD</Implementation-Vendor>
-              <Implementation-URL>http://www.amd.com/</Implementation-URL>
+              <Implementation-URL>https://gerrit.googlesource.com/plugins/manifest-subscription/</Implementation-URL>
 
               <Implementation-Version>${project.version}
               </Implementation-Version>
diff --git a/src/main/java/com/amd/gerrit/plugins/manifestsubscription/VersionedManifests.java b/src/main/java/com/amd/gerrit/plugins/manifestsubscription/VersionedManifests.java
index 44b5889..3c779d1 100644
--- a/src/main/java/com/amd/gerrit/plugins/manifestsubscription/VersionedManifests.java
+++ b/src/main/java/com/amd/gerrit/plugins/manifestsubscription/VersionedManifests.java
@@ -161,6 +161,12 @@
 
   @Override
   protected boolean onSave(CommitBuilder commit) throws IOException {
+    // extra commit message (such as the one-liner git log) is put in
+    // the body because:
+    // 1) not all manifest update has a one-line git log (such as
+    //    the manifest generated from the initial subscription)
+    // 2) An manifest update may contain multiple project, which means
+    //    multiple one-line git log
     StringBuilder commitMsg = new StringBuilder();
     commitMsg.append("Snapshot manifest from " +
         srcManifestRepo + " updated\n\n");
diff --git a/src/main/resources/Documentation/about.md b/src/main/resources/Documentation/about.md
index 79a76fd..96f17ea 100644
--- a/src/main/resources/Documentation/about.md
+++ b/src/main/resources/Documentation/about.md
@@ -48,6 +48,13 @@
 * Parsed manifests are kept in memory for quick lookup
 
 
+Development Notes:
+------------------
+Entry points for this plugin are:
+ * ManifestSubscription.onGitReferenceUpdated() (for event driven activities)
+ * SshModule (for ssh commands)
+ * HttpModule (for REST/http commands)
+
 ```
 xjc -dtd -d gen -p com.amd.gerrit.plugins.manifestsubscription.manifest manifest.dtd
 ```
@@ -74,5 +81,3 @@
 * TODO: include an external manifest DTD or XML schema/XSD
 * TODO add test verify manifest that can cause circular conditions
 * TODO sub dir include manifest have same level include working
-
-