keep track of [85c5f2f] and fix several typos

keep track of [85c5f2f](https://github.com/sbt/website/commit/85c5f2f1172d0c927d050c9f2f3fe347a9edaba9),  include the pr in [pr78](https://github.com/sbt/website/pull/78)

and fix several typos in document.