Provide instructions for users who would like to run tool from source

[glemieux]

Option A: https://pip.pypa.io/en/stable/topics/local-project-installs/

[glemieux]

The most straight forward way to do this is by running from the src directory the following command:

conda run -n <environment> python -m landusedata <subcommand> <positional args>

Notes that this assumes that the user has installed the necessary dependencies in their own conda environment.

For my future self, the reason to do this is that the package is intended to be entered via main.py. The -m tells python to set __name__ to __main__ for the module directory being called.