Update docs to have link to donation link. :)

[NathanaelA]

**Is your feature request related to a problem?
Not easy to find link...

Describe the solution you'd like
A link in the docs for donation. It is in the windows code; but most people aren't going to scan the windows code to find it, if they are using linux... :D

Additional context
https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=HUALCC9HY9MKC

[hirschmann]

Fixed :D
I hope a paypal link in the readme isn't considered too annoying.

[NathanaelA]

@hirschmann - I don't think anyone finds a paypal link in the docs annoying. But it will help those of us on Linux (which I run 99% of the time) be able to donate a lot lot easier...

I wouldn't have had a clue where to donate to, if I hadn't noticed earlier in the day a link in the Windows version that I had also just installed. So, I knew that I could probably find it somewhere in the source code... :-)

I am VERY happy this app supports Linux -- I had tried a dozen or so apps/ways several months back and none of them worked, so I had basically given up. And so my computer frequently overheats and throttles down my cpus to crazy slow speeds... So solving a major headache for me, was well worth a donation... 😀

[hirschmann]

Thank you very much for the donation, I'm always glad to hear I was able to help someone solve their problems. :)