Various documentation updates focused around surfacing feedback article

Summary:
missed doing this for phame, so i poked around a bit and added it to
similar verbage as well as to a few "Next Steps" where I thought the feedback
might be provocative.

Test Plan: read the docs

Reviewers: vrana, epriestley

Reviewed By: epriestley

CC: aran

Differential Revision: https://secure.phabricator.com/D2220

src/docs/userguide/audit.diviner

@@ -104,4 +104,5 @@ only changes that are relevant to them.
 
 = Next Steps =
 
-  - Learn more about Herald at @{article:Herald User Guide}.
+  - Learn more about Herald at @{article:Herald User Guide}; or
+  - give us feedback at @{article:Give Feedback! Get Support!}.

src/docs/userguide/differential.diviner

@@ -65,4 +65,5 @@ files affected, etc.)
   - learn about handling large changesets at
     @{article:Differential User Guide: Large Changes}; or
   - learn about test plans at @{article:Differential User Guide: Test Plans}; or
-  - learn more about Herald at @{article:Herald User Guide}.
+  - learn more about Herald at @{article:Herald User Guide}; or
+  - give us feedback at @{article:Give Feedback! Get Support!}.

src/docs/userguide/diffusion.diviner

@@ -144,4 +144,11 @@ You can add new classes which will extend or enhance Diffusion's ability to
 parse commit messages.
 
 TODO: This is an advanced feature which doesn't currently have documentation and
-isn't terribly stable.
+isn't terribly stable.
+
+= Next Steps =
+
+  - Learn about creating a symbol index at 
+    @{article:Diffusion User Guide: Symbol Indexes}; or
+  - give us feedback at @{article:Give Feedback! Get Support!}.
+ 

src/docs/userguide/phame.diviner

@@ -15,4 +15,4 @@ of the Phabricator instance must properly configure Phabricator to enable
 this functionality.
 
 NOTE: Phame is extremely new and very basic for now. Give us feedback on
-what you'd like to see improve!
+what you'd like to see improve! See @{article:Give Feedback! Get Support!}.

src/docs/userguide/phriction.diviner

@@ -9,4 +9,4 @@ Phriction is a simple wiki. You can edit pages, and the text you write will stay
 there. Other people can see it later.
 
 NOTE: Phriction is extremely new and very basic for now. Give us feedback on
-what you'd like to see improve!
+what you'd like to see improve! See @{article:Give Feedback! Get Support!}.