Pyknos

- **Bumped Version**: Updated version and README.
- **CI Updates**: Separated linting and testing actions.
- **Documentation**: Updated docs and improved handling of hidden features.
- **Bug Fixes**:
- Fixed docstrings and embedding-net handling messages.
- Resolved issues with batched sampling and associated tests (35).
- Fixed CI configurations and Pyright errors.
- Corrected version retrieval process.
- **Enhancements**:
- Added contribution guide (5) and code of conduct.
- Replaced setup with `pyproject.toml`.
- Refactored CI; added pre-commit hooks and formatting.
- Extended tests (32).
- **License Change**: Switched to Apache 2.0 (28).
- **Miscellaneous**: Performed Ruff checks and automatic fixes.

- Replace `torch.triangular_solve()` with `torch.linalg.solve_triangular` (26).

- Fixes to version v0.15.0, in which the release did not contain the desired fixes.

- `epsilon` is added after multiplication of Cholesky-factors for better numerical stability (22)

- fix device bug in analytical MoG sampling (19).

- refactor MoG to allow evaluation with analytically determined parameters (17).