initial project setup

[chrishavlin]

Adding initial project configuration.

Some notes:

• package should now be installable with pip install -e .. Only have yt>4.2 as a dependency for now, will want to add to that as needed.
• CI: just a single workflow for now to run pytest
• style: I initialized the pre-commit config and related tool settings in pyproject.toml following yt, but tried to simplify where we can

[matthewturk]

Thank you!