Updated 'notmyidea' theme, to be 'link post' capable.

Link posts seem to be the most requested feature. Since Pelican can support it by default, 'notmyidea' theme is updated to support it out of the box for an example.

This addresses issue #565

See an example of the output visit: http://pelicantests.site44.com/

**This is not ready to be merged.** 

Please review and provide feedback as well as were to document this capability. Since it is a 'requested feature' that Pelican supports out of the box, I was thinking the _FAQ_.  Sound ok?