By GitHub around Black Lives Matter, due to a possible ludicrous relationship with slavery of black people:
For the love of God, the word "master" is much more general than black slavery. If you are going to ban it, you might as well ban the word "evil".
Several software projects followed the purge from their codebases, maybe GitHub followed someone else's lead, it's hard to say.
The words "whitelist" and "blacklist" were also targeted.
If Ciro Santilli were to write a book about quantum mechanics as of 2020 (before OurBigBook.com went live), he would upload an OurBigBook Markup website to GitHub Pages.
But there is one major problem with that: the entry barrier for new contributors is very large.
If they submit a pull request, Ciro has to review it, otherwise, no one will ever see it.
Our amazing website would allow the reader to add his own example of, say, The uncertainty principle, whenever they wants, under the appropriate section.
Then, people who want to learn more about it, would click on the "defined tag" by the article, and our amazing analytics would point them to the best such articles.