Add linklog posts

This pull request adds linklog posts from [chrisfrederick.net](http://chrisfrederick.net/archives/) and makes a few other minor improvements:

- Hides months with only linklog posts from the archive (b0a815be1e510565dcf1bd41fcf442bc02f5724a)
- Adds all posts to the RSS feed (ae3a9e8f4a5cfeda38551f8fd26033cbeaba2ab6)