Support $XDG_CONFIG_HOME for config location

[thecodejunkie]

Hi

First of all, love rectangle! I was wondering if there are any plans on support alternative config locations? Many tools support their own (like Rectangle) directory but also $XDG_CONFIG_HOME with fallback to ~/.config if it's not been set. This makes it very convenient to store your configurations in a dotfiles repo

Would be great if ~/.config/rectangle/RectangleConfig.json was supported

[rxhanson]

Not what you're looking for, but there is the existing functionality for loading the config from ~/Library/Application Support/Rectangle/RectangleConfig.json, which could potentially be symlinked or this could be built on in order to achieve this desired outcome. There are limitations to be aware of with the current implementation, as noted in #893 and #1246.

I don't have plans to add in exactly what you're looking for at this time, but see no reason to turn down a good pull request for it.