Add documentation for rendering simple cms pages in menu.

| Q             | A
| ------------- | ---
| Doc fix?      | no
| New docs?     | yes #334 #90
| Applies to    | ~1.0
| Fixed tickets | #334 
can you please update this list to be a definition list? http://docutils.sourceforge.net/docs/ref/rst/restructuredtext.html#definition-lists