[Feature request] XDG compliance

[erisdev]

I don't know if you're interested in updating this, but I've got a couple minor gripes on the off chance you are:

• The configuration file should be something like $XDG_CONFIG_HOME/huekeys.toml or $XDG_CONFIG_HOME/huekeys/config.toml, not ~/.huekeys. Putting dotfiles directly in the home folder creates clutter. I think it would be reasonable to also check the old location as a fallback.

• The socket and pid files by default should go in $XDG_RUNTIME_DIR. This is where any user-specific ipc sockets, temporary files, etc. belong.

See the XDG Base Directory Specification for details if you're not familiar with the standard.

(Great tool otherwise. I appreciate the IPC socket the most. I'm using it to signal notifications by changing the keyboard backlight to my i3 urgent window color)