This post doesn't really give a new user guidance on using the category or Discourse for CMunities - it's more of a discussion topic in itself! If you look at other discourse forums the pinned posts in categories really only define the scope of the category. For example the meta.discource bugs category:
A bug report means something is broken, preventing normal/typical use of Discourse. Do be sure to search prior to submitting bugs. Include repro steps, and only describe one bug per topic please.
We need to decide on the rules in this case. We probably want people to respond in the relevant subcategory and only start a topic in Communities about starting a new community or similar, but other structures could work.
I would suggest moving the community structure info to the website and providing a link here, we should also remove things like BDFL and rewrite the structure for an external audience who know nothing about ContentMine - PMR was brain dumping for the weekly meeting here.