Support templating

[pawandubey]

Support one tempating engine for styling the site, with some prebuilt templates (for index, archive, 404, post, page, about). The current possible candidates of templating engines are:

• Rythm
  • Fast, but needs declaration of variables. Not dynamic. New.
• Freemarker
  • Slower than Rythm, but mature and ubquituous. Dynamic. No declaration needed.

Templating engines are needed so that data can be injected into the HTML templates to produce files. Eg. firstpost.md will be rendered with the template post.html to give firstpost.html. Also needed to inject site-wide variables like site-name and author etc.

[pawandubey]

Going with Rythm Handlebars.java on this initially for speed simplicity.

[pawandubey]

Done in 6b77f0e