Adds comments to sample modules.
Updates key chord bindings.
Merge pull request #457 from climatewarrior/updateKeyChords

Updates key chord bindings.
Merge pull request #456 from climatewarrior/add-module-docs

Adds comments to sample modules.
Minor change
Merge remote-tracking branch 'prelude/master'

* prelude/master:
  Updates key chord bindings.
  Adds comments to sample modules.
Add comments in prelude-modules.el