@roman_r_m you might be interested in the prettier code formatter. I had originally written a "Prettify Selection" command into my rich markdown plugin, but unfortunately it does not work on the current version, so it's been commented out for awhile. You can see the code I used here.
In any case I think that kind of functionality is probably better in a separate plugin. If you're interested I think it would be great to combine the prettier tool with your plugin. I'd be happy to help contribute as well if you'd like.