Initial feedback fixes

Hey, first of all thank you all who played my game and gave feedback either in comments or in feedback form at the end of the game.
What changed:

• Bigger UI for upgrade windows for both defenders and buildings
• Additional image which defender is currently selected
• Bug fix of being able to do multiple upgrading
• Initial market will always have all type of starting buildings
• Enemy difficulty lowered a bit, starting levels will be tougher and later one's will not get so bad so fast
• Some typo's, missing sounds, and other quality of life improvements

Thank you all for playing and hoping to hear more feedback soon and to return with more content!