I don't know of such a list. I think there are not many really new features, but a lot of issues have been fixed and it is much improved overall. I strongly recommend to use 2.2.0 rc, it is stable and the user manual https://librecad.readthedocs.io/en/latest/index.html refers to this version.
I am the new one on forum so mayby is not good place for my question but I try because it seams that I have similar topic.
I imported JPG pictures to Libre and I can scale ( set it as block) but screan completelly cover my previous roject and I cant move/set pictures as background.
Is it possible to set that pictures as backround or set level transparency or "move to the bottom"?
Of course you can send an image to the background by "Move to Bottom". But it still stays being selected after that, and as long as it is selected it will visually be in the foreground. You have to deselect it by "Escape" to see the final result.