Massive update to the code list (see notes)

- There are now 146 known code/key pairs, nearly tripling the list from
  the 50 known pairs before
- Ensured all code titles were precisely as shown in Torque Pro
- Master list is now kept in codes.in, with a new generate.py script
  that reads the list and turns it into the pretty thing in codes-list.md
- Created a doc directory for all this
- Removed this from the TODO; huzzah!