This commit fixes the following bugs:
- A guy in Celadon University was stuck in a tree due to being placed on the wrong tile.
- It was possible to walk out of bounds in Mt. Moon Crater due to buggy collision near the bottom of the map
- Hi Jump Kick had a slightly glitched animation
- It was possible to walk into a specific rock in both Cerulean Cave and Garnet Cavern. This was a vanilla bug too, but I'm fixing it proper now.
- There was no signpost outside Bill's Lighthouse where there should've been.
- Fixed two errors in the README
- The Fissure TM was not purchasable at the Citrine Rocket house
- Even if you had picked one of the original starters, you could still get the Charmander and Squirtle gifts as the NPCs would show up regardless.
- Trying to get the Squirtle gift with a full party and box would lock you out from getting it
- Fixed a text issue in Celadon Uni where the professor states the wrong TM
- Fixed two text issues in Silph Co
Currently the move tutor is a little bit broken - the IDs are 1 above how they should be. Shell speculates that it's searching at the table starting from Kangaskhan due to the way the decrements shake up but it may just be making things more complicated than they are.
Big cheese code is `PrepareTradebackMoveList`, it's where things are mucking up.
Also, the code can be significantly optimised, as it's currently being adapted from the function above, `PrepareRelearnableMoveList`; It doesn't need to check levels, for example.
Note that the relearner functions properly, so use it as a reference. I may have removed something important.
Technically, we could have NO_MON as an entry which may make things shake out properly. But I'd rather have a proper fix.
Underwater Tunnel is a new area that links Route 25 to Route 10, basically just being a straight tunnel needing Surf to traverse.
Also given Seafoam Islands and Lorelei's room an unused palette that gives it a more icy feel
