Add WORKING_DIRECTORY environment variable to .env file

[dano-gobodhi]

Just an idea, since load_cfg.py file is loading environment variables and it's looking for a WORKING_DIRECTORY variable which isn't included in the example .env, replacing it with './data_storage' which may not be where the user has their data stored.

[starpig1129]

You're right. That's the old version of the variable name.