Refactor: Test & Doc: Remove test/vader_include and move DesignNotes to doc

- vader_include is declareing functions -> faster to load (parse) once in
vimrc
- DesignNotes is doc so goes to doc

test/diary_rss_feed.vader

@@ -1,4 +1,4 @@
-Include: vader_includes/vader_setup.vader
+# Feature to generate a diray RSS feed (PR #934)
 
 Execute (Copy Wiki's Resources):
   Log "Start: Copy Resources"
@@ -106,5 +106,3 @@ Expect (RSS):
    </item>
   </channel>
   </rss>
-
-Include: vader_includes/vader_teardown.vader