The documentation is out of date

Remember [doc/](https://github.com/aelzenaar/tightframes/tree/master/doc)?

 - [ ] Rewrite the explanation of the iteration algorithm.
 - [ ] Write up explanations of the options for the Python scripts.
 - [ ] Explain how to interpret error graphs and badness.
 - [ ] Document difference between `errorExp` and `errorMultiplier`.
 - [ ] Explain how to interpret `project.py` visualisations.