Update AUR installation instructions
Update AUR installation instructions

This fixes #117.

thoughtbot/pick,calleerlandsson/pick,DBOTW/pick,prahlad37/pick,calleerlandsson/pick,thoughtbot/pick,calleerlandsson/pick,prahlad37/pick,thoughtbot/pick,prahlad37/pick,DBOTW/pick,thoughtbot/pick,prahlad37/pick,DBOTW/pick