Web code editor should be better at editing markdown
In-repo markdown files are treated as code and opened by the usual web code editor. This gives a very limited markdown editing experience (basically only code highlighting and preview tab), especially when put alongside the comparatively stellar experience of editing comments and issues. This is particularly egregious when editing or fixing in-repo documentation, and even more so for non-tech folks that don't want to bother with cloning locally.
Enhance the code editor when editing markdown, or possibly replace it with the same editor as the one available for issues and comments.