Community Feedback Update

This latest update contains a number of changes inspired by player feedback over the past week:

• Added a new "Command History" upgrade to the shop. This enables the use of the up/down arrow keys to select previously sent commands. (based on a suggestion from /u/ascii122)
• Changed purchase syntax to "buy X" and added a "buy max X" command for purchasing the max affordable number of a specific upgrade/employee. (based on a suggestion by ntscheel)
• Added a clicking sound on manual clicks. (based on a suggestion by my boy Chris)
• Added a mute toggle, just in case you want a silent experience.
• Added an easter egg. (based on a suggestion by Jacob)
• Some other boring stuff related to the save backend.

Thanks for all the feedback! I hope you all enjoy the newest updates.