Update to version 21.04

This update mainly adresses game functionality on linux.

• added fullscreen option on linux
• fixed an issue with dual screen setups on linux
• fixed numpad enter key not working on linux
• added a score multiplier because the game got a lot harder after the last patch
• added coloring in the character sheet when stats are changing (stat turns red for a negative change and green for a positive one)
• added a few missing german translations
• fixed a bug where your strength won't be updated after a giant ant or centipede stung you
• fixed a bug where a broken ladder on a hole in the ceiling would cause the player to fall into a pit
• fixed a few issues with altars in the temple

Also we made a twitter account to do stuff like community actions, giveaways and showing new features in development.