Changelog:
- [Add docstrings](https://github.com/mBelisarius/thercy/commit/da4cce1d5a39c64f19265e4645fd0aa54b62338d)
- [Update examples](https://github.com/mBelisarius/thercy/commit/2ce711dda5550881079362de850af3a4131c0e17)
- [Add optimization example notebook](https://github.com/mBelisarius/thercy/commit/497f9594dd8ee3fd0f6e004c9cdf30c6afa97b15)
- [Fix fraction unit and update examples](https://github.com/mBelisarius/thercy/commit/c07cfa89c96151e2484f7fea7f6626da5cefa6b0)
- [Remove StatePoint and refactor state handling](https://github.com/mBelisarius/thercy/commit/5e2ca4f9422a84394f227d206813a2d231434b60)
- [Refactor solver for 10x speedup by switching to linear conservation laws](https://github.com/mBelisarius/thercy/commit/c371b7a71241c4b307194b1246a8fbd5243fc1c4)