You can put that in a README, but people won't read it. Github won't let you disable i̶s̶s̶u̶e̶s̶ ̶l̶a̶s̶t̶ ̶I̶ ̶l̶o̶o̶k̶e̶d̶ pull requests, unless you archive the project (making it read-only). Is it possible on one of the other hosting services, like Gitlab?
We need better ways to draw boundaries around open source projects and contributors.
ETA: How can we counter the Bullshit Asymmetry Principle? https://en.wikipedia.org/wiki/Bullshit#Bullshit_asymmetry_pr...
> The amount of energy needed to refute bullshit is an order of magnitude bigger than to produce it.