Ionizer

Mostly improvements to development processes, with a few feature upgrades.

New features and upgrades:
- Equivalence checking can now be performed in the background on all transforms
- Ionizer is upgraded to work with PennyLane 0.37 and Python 3.12

Improvements to development processes:
- set up pre-commit hooks and CI pipeline to format and lint code, and run tests
- switched dependency management to Poetry
- documentation now renders on readthedocs
- library is installable via pip

This release updates the Ionizer transforms to use the new transform machinery in PennyLane v0.33 (which is now the minimum supported version of the package).

It also improves test coverage of some utility functions.

v0.1 contains the operations, a basic set of transpilation routines, and single-qubit gate optimization.