[anti-spam] a mechanism for asking a question on edit

In my experience, asking a simple question with a one-word answer on every edit AND enabling rate limiting has proven to be super effective on a public wiki that I admin. We haven't had any spam breaches in over 5 years now, and we are also indexed by search engines. The plugin that I used: https://www.mediawiki.org/wiki/Extension:QuestyCaptcha

I prefer this method because it does not leak user metadata to recaptcha/google or any other 3rd party service.

I'm creating this issue to gauge interest for a gitit plugin, and also so that I don't forget to learn haskell and write this plugin eventually.