​v0.2.3 - Post 7DRL fix

Keeping the scope of the original 7DRL version, this patch contains:

• Add a tutorial level with tips to learn how to play.
• Text tweaks in the help screen
• Remove "piety" indicator from UI
  
• Fix crash when throwing enemies in cramped rooms.
• Fix minor bug with level 1 music not being played from the beginning.
• Fix bug with reload sound not playing the turn you ran out of ammo.
• Fix bug preventing R to restart the game if dead while stunned.