Change getmaps.lua

just being curious. Is there a way to change the getmaps.lua so that it stays?
I just want to organise my map collection a bit, add entries for sin, neotokyo and such.
The problem is, that the moment I start gmod it seems to reset the lua to it’s original state.
Even tried hiding it, make it it read only. No matter what I do, it get’s thrown out.

Any tips would be welcome. Even alternative ways of getting more map categories.