Allow the user to place a configuration file in $XDG_CONFIG_HOME/spells supporting at least the following options:
- List of sets as "all_sets"
- Default columns
- a python script containing column extensions
- logging configuration
- streaming mode default
- gpu mode default (when supported)
- data directory
- pandas output
- group agg columns by expansion (e.g gih_wr_z)
Allow the user to place a configuration file in $XDG_CONFIG_HOME/spells supporting at least the following options: