Donations: Provide ability to contribute

[davidfstr]

Tasks:

• [ ] Research/enable Donate button on GitHub. (See screenshot below for knob to twiddle.)
  • [ ] Create personal GitHub Sponsor page for myself
  • [ ] Verify payment processing works by giving self a donation at a reference price. Perhaps 20 USD?
• [ ] In the About Box, mention ability to contribute:

  • If you find this software useful consider making a donation to the [core contributors] (LINK to GitHub Sponsor page).

• FUTURE: When a contribution-required feature (like export/distribution or distributed crawling) is introduced, bring up a prompt when a non-contributing user attempts to use the contribution-required feature

Enabling Donate button on GitHub:

[davidfstr]

Note: Be careful about using the word "sponsor" in URLs related to this feature. Apparently many ad-blockers assume that "sponsor" in the URL indicates an ad, which should be blocked.