Add PayPal and ko-fi donation links to Donation section

[JohnTHaller]

The donations section of the documentation currently only links to Patreon:

https://www.oramainteractive.com/Pixelorama-Docs/development_and_contributing/#donations

I'd suggest adding both the PayPal donation and Ko-fi donation links to the same section so users have all options available. While these two options are available on the main Pixelorama project page on Github, they aren't available in the Donations section of the documentation.

Context: I just released a Pixelorama Portable package at PortableApps.com and am linking to the Donations section of the documentation so users can donate and it'd be helpful to have all options for folks there.