Just extract the files to the main Amnesia:TDD catalog and it should appear on your list.
So... it's been a while. I tried my best and considered Your tips while creating and designing locations as well as scripting. Unfortunately old maps still look bad and there was not much for me to do to improve it so I couldn't do much more but just add better lighting (which ain't the best as I'm just bad at it), so I focused on the new ones instead.
It's about 60% done of what I've planned... I dunno, we'll see. It isn't that hard but definitely tiring. Cons of working alone ¯\_(ツ)_/¯
Sharing it now so maybe some bugs may be spotted and fixed.