Discourse provides RSS feeds for all posts and for all categories and tags. Unfortunately, it's not that obvious, so I'm writing it down here:
→ this is the RSS feed for alle new posts
Additionally, you can append ".rss" to most URLs to get a specific RSS feed:
→ this is an example RSS feed for all new topics in the category UCS@school
→ this is an example RSS feed for all new topics with the tag "docker"