Added configuration for prose

As mentioned in #14, added configuration to prose to allow for an easier
interface when writing blog posts. Excluded unneeded files and folders, setup
a media folder, added the hidden blog field, and create a tags field where a
user could enter in multiple tags.

Could use more specs on what other UI this would need to be successful. Are there
other fields to include in the meta data? Are there a set of tags we want to 
provide by default? Should any other dirs be excluded from prose?