Generating Page, Post, and Comment _data files.

Switched up the script to generate _data files instead of piping out to
stdout. While this goes against my love of C's way of text, text
everywhere it makes sense for some of these reasons:

 Harp .json files aren't arrays, they're long lists of dictionaries.
 Harp .json files are seperated out by their data, so it makes sense to
seperate the output of this script as well.

Next steps are probably to make the script more configurable (dont
include draft posts etc etc) and then have it generate the files
themselves, or at least some kind of useful harp files or layout.