**Is your feature request related to a problem? Please describe.** Despite `fjira` being so awesome :wink:, it keeps cluttering my `$HOME` dir with its cofig dir. **Describe the solution you'd like** Using `$XDG_CONFIG_HOME` env var would make more sense. **Describe alternatives you've considered** N/A **Additional context** Spec docs: https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html