revumatic doesn't respect XDG_CONFIG_HOME
From https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html#variables
$XDG_CONFIG_HOME defines the base directory relative to which user-specific configuration files should be stored. If $XDG_CONFIG_HOME is either not set or empty, a default equal to $HOME/.config should be used.
It would be great if revumatic could use that directory instead of adding more stuff in $HOME directly.