Folder for sharing forcing data

[Peter9192]

ewatercycle.forcing.generate() creates forcing data that is reusable by ewatercycle.forcing.load()

It would be good to have a default (r/w) directory where we store forcing data that is intended for re-use or exchange. Many of our example notebooks currently use or would benefit from pre-generated forcing data, but currently, the location where this data is stored is very arbitrary.

[Peter9192]

I suggest /mnt/data/forcing

[sverhoeven]

I put the https://github.com/wknoben/MARRMoT/raw/master/BMI/Config/BMI_testcase_m01_BuffaloRiver_TN_USA.mat in {{ example_forcing_root_dir }}/MARRMoT/BMI_testcase_m01_BuffaloRiver_TN_USA.mat where example_forcing_root_dir is `/mnt/data/forcing

[Peter9192]

Created /mnt/data/forcing on jupyter machine and filled with:

lisflood_ERA5_1990_global-masked/
marrmot-m01_ERA5_1990-2001_savannah/
marrmot-m01_ERA5_2001-2016_moselle/
marrmot-m01_example_1989-1992_buffalo-river/
wflow_ERA5_1990-2001_merrimack/