Sax

Added
- Documentation and examples.
- Coercion of nets into connections.
- Handle for callable instances in connections.
- Tests for cleanup and refactoring.

Deprecated
- `info` subdirectory in instance dictionary.
- `sax.nn` module.

Updated
- Proper transition to `pydantic v2`.
- Added docstrings across functions (34).

Updated
- Pinned minimum version of `flax`.

Fixed
- Minor bug fixes.

Added
- Config setting to override component in `info['model']`.

Updated
- Bumped `klujax`.

Improved
- Flatten netlist functionality.