Quiver
You can use quiver by copying the embed code and then pasting it into your post, like the following
When editing your post, quiver constantly refreshes on every edit, so you can comment it out with <!-- quiver embed --> until you are done editing.
Collaborative editing
You can use docs.localcharts.org to write posts collaboratively in markdown, and then copy-paste them into the editor here. (TODO: set this up)
RSS
Almost any page on discourse can be turned into an RSS feed by adding .rss to the end of the URL.
Full-screen mode
You can go into full-screen mode while editing a post by clicking on the arrows in the top right corner of the edit box.