[1] repo setup: tests, linting, ci, typing

[Ben-Epstein]

this gets us started on our path to open source.

1. setups up invoke for managing the project
2. adds linting, formatting, and typing to training -- other 2 folders to come
3. sets up ci/cd for training -- other 2 folders to come
4. type-hints all of training -- other 2 folders to come