update docs

Author: nix

docs/app/docs/user-guide/ofs-integration.md

@@ -73,7 +73,7 @@ Yo can use my OFS Fork with nix support. My OFS Fork includes the MTFG Extension
 nix run github:michael-mueller-git/OFS --refresh
 ```
 
-Limitation: The nix package is stored in a read only filesystem path. You can currently not change the config files for MTFG.
+The config files for nix version are stored in `~/.config/mtfg`.
 
 **At first lauch of the MTFG Extension nix need to build all dependencies for MTFG this may take several minutes! You may want to run `nix run github:michael-mueller-git/Python-Funscript-Editor --refresh` once before using the extension in OFS to see the current build process output.**