Consolidate declaration and definition documentation

[speedyleion]

Conversation from #10 ,

One idea I've been trying to consider, is doing like doxygen and combining the documentation from the declaration and the definition. I think it would require an option to let the user specify if the docs go at the declaration or the definition location.

I think adding something like this would be incredibly useful, especially if also integrated with the viewsource extension, which would allow the developer to define the documentation in a header file, have it show up in the source (or header) and have it link to the source code.

The main idea is to consolidate any documentation in the declaration with that of the definition.
Some things to consider:

• As @wynn-rj mentioned viewsource should probably default to linking to the definition.
• If autocmodule is used where should the resultant documentation end up? Doxygen appears to only put it with the header (declaration). The header may be a good initial default.