Repeng

* Fix a bug in control.py (18)

* Add GPT-2 support. (12)
* Officially support Python 3.10 and 3.11. (13)

* Add control vector arithmetic. (6)
* Add GGUF export. (5, 9)
* Notebooks: Add code questions dataset. (4)
* Notebooks: Move `data/` to `notebooks/data/`. (7)
* Notebooks: Add MPS (Apple Silicon) autodetection. (8)

* Initial release.