Fix inheritance in configuration file

[forsyth2]

Specifying mapping_file = /home/ac.zender/data/maps/map_ne30pg2_to_cmip6_180x360_aave.20200201.nc under [default] results in creating <output>/post/atm/native whereas specifying the mapping file under both [climo] and [ts] results in creating <output>/post/atm/180x360_aave/.

It's likely the mapping file specified at https://github.com/E3SM-Project/zppy/blob/main/zppy/templates/default.ini#L20 and https://github.com/E3SM-Project/zppy/blob/main/zppy/templates/default.ini#L44 ends up overriding the value set in [default].

Possible solution: move parameters as high up in the default.ini hierarchy as makes sense.

[golaz]

@forsyth2 : good catch! Moving the definition of the default value to the [default] section should solve the problem. It's a good opportunity to go through the list of default values and move non-task specific ones to [default] as well.

[forsyth2]

Note: while addressing this, it may be useful to alphabetize parameters in each section as well.

[forsyth2]

It may be good to simply add comments to default.ini and direct users there rather than duplicating the parameter list at https://e3sm-project.github.io/zppy/_build/html/main/parameters.html. (Duplication can go out of date quickly).