To do list

[TAJD]

Moving the to-do list from the readme:

1. ~~wrap rig into yacht class~~, and update measure functions
2. validate on YD-41 (Principle of Yacht Design), and write tests
3. ~~optimize the boat velocity with the 3-DOF equlibrium as constraints (Lagrange multipliers)~~
4. Add all the windage contributions (mast, crew, rigging, etc.)
5. Optional Delft hydro model
6. Add dagger boards to the possible appendages
7. ~~tidy plotting and results~~