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/list_update.vader

@@ -1,4 +1,4 @@
-Include: vader_includes/vader_setup.vader
+# Task list update
 
 Given vimwiki (Sample nested list, vimwiki syntax):
   * [ ] Top Level
@@ -188,4 +188,4 @@ Expect (Sub-child toggled, parents updated):
 
       * [X] Sub-sub-child
 
-Include: vader_includes/vader_teardown.vader
+# vim: sw=2:foldlevel=30:foldmethod=indent: