Scary branch name
Merge branch 'jrh-remove-knowledge' of https://github.com/jrhorn424/arlingtonruby.github.io into jrhorn424-jrh-remove-knowledge

* 'jrh-remove-knowledge' of https://github.com/jrhorn424/arlingtonruby.github.io:
  Scary branch name

Conflicts:
	index.html
Add link to retro, remove the one to knowledge.