Update 0.8.1

A smol update with some bug fixes, new tutorials, updated radio, and highest delivery rank tracking.

Changelog : 

• Fixed extreme lag/floating tank bug that sometimes happened when loading a save
• Game version now shown on main menu and in game
• Added warning popup when trying to load old saves on new versions.
• Progress on adding old save compatibility
• Repeating deliveries now show the highest rank you have completed
• Repeating deliveries respawn after 30 minutes now, not 60.
• Removed useless variables from delivery missions
• Added tutorial mentioning how to leave act 2
• Added HUD prompt for using shop items
• Default radio sound quality is now much worse
• Added speakers upgrade for radio at hydro
• Added headphones upgrade for radio at radiotrician
• Added new radio songs
• Added character comments to if you drive up to ice covered tunnel to metro before cleaing it with a bomb
• Wireframes for main menu tank, upgrades and deliveries is no longer see through
• Adjusted some upgrade prices
• blocky landscape bug should now be fixed more reliably
• Removed bridges/tunnels under map
• Removed floating blender default cube
• Updated patreon credits