Implement SPAM reporting (XEP-0377)
https://xmpp.org/extensions/xep-0377.html allows to report SPAM to server administrators, which is a desired feature regarding recent SPAM waves.
The XEP is quite simple (a unique <IQ> request) and so may be a good entry point for anybody desiring to start contributing on SàT.
It may be implemented with text commands, and it should be similar to https://bugs.goffi.org/bugs/view/211