Some new styles

- Headers are now centered and in Open Sans Light
- Dates are monospaced
- Global footer enhancements include brighten-on-hover, fade transition
- Adds link to latest post on home page
- "Writing" renamed to "Posts" (redirects from `/writing/*` to `/posts/*` in place)
- Projects now independent of Jekyll posts
- Theatre resume now generated from `_data/shows.yml`