Post-release bugfixes: Batch 1

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

text/VermilionCity.asm

@@ -215,6 +215,11 @@ _OfficerJennyText3::
 	line "SQUIRTLE right!@"
 	text_end
 
+_JennyFullParty::
+	text "Your PARTY is"
+	line "full, though!"
+	done
+
 _OfficerJennyText4::
 	text "Oh... What am I"
 	line "to do now?"