added an article on chairs
Merge branch 'source' of github.com:artsy/artsy.github.com into source

* 'source' of github.com:artsy/artsy.github.com: (21 commits)
  Updated, explaining why sorting by _id is also important.
  Updated link.
  Updated with information from the thin mailing list on EventMachine routing.
  Added links.
  Draft: The Impact of Heroku's Routing Mesh and Random Routing
  Infinite Scroll with MongoDB
  Art.sy to Artsy
  Added https://github.com/aaw/space-saver-redis.
  Added https://github.com/aaw/cartesian-product.
  Minor language updates.
  Fixed typo.
  Final post draft.
  Draft: Concurrent Updates to Embedded Objects with Mongoid.
  Minor corrections.
  Draft: Master Heroku CLI with Heroku Commander.
  Ooops, system! is something we have.
  Create MongoDB command lines with mongoid-shell.
  Improving performance of mongoid-cached-json.
  Replaced art.sy with artsy.
  Finalized post.
  ...
Merge branch 'source' of github.com:artsy/artsy.github.com into source

* 'source' of github.com:artsy/artsy.github.com:
  Added a note on the Empire State Building.
  An Easter Egg for Curl.
added chairs to open source