Add way to tip author

[Al Berez]

Is your feature request related to a problem? Please describe.
This app is life-changing for many unlucky macbook users. Some would like to support this open-source product and reward the author.

Describe the solution you'd like
Add a link to the tip jar on the GitHub page and potentially inside the app. Make the donation options one-time and recurrent. Figure out a fair way for active contributors to become a core team and get some share.

Describe alternatives you've considered
There is no alternative to supporting hard work by tipping. Rewarding the author's kindness by making this available to everyone for free is the right thing to do.