Demo update

Demo version has been updated to v1.0-alpha, and this will probably be the final demo version before full release. Content has stayed mostly the same, but there are a number of QoL changes and improvements:

• Multiple save files
  
• Reworked settings screen
  
• Reworked party screen for easier swaps
  
• Steam achievements (5 are obtainable in the demo)
  
• More tutorials on TP and other early game mechanics
  
• Starter tech tweaks and buffs
  
• Tenn (the TV forest man) can now heal your party