Steam achievements

OBS Python Steam achievements v2.1.1

Added cache and a (potential) bug fix
Output is more customizable
Added currently playing + completion percentage
Cleaner in general
No difference in usage, cleaned up some code and included played free games in GetOwnedGames API-call. If you notice that this calculated percentage is different from the one in your Steam profile showcase, please check if you own all the games for which you have any achievements.