by Firefox user 13899646, 3 years ago
Rated 5 out of 5
Note that the author notes that the extension only works "if the content is plain text". That means your browser needs to be rendering the file in a tab already, just without rendering the markdown elements. If it's downloading it instead, the suggestion from 7cac17 below, to add a MIME type for markdown files, worked for me (I'm also on Ubuntu).