Clean up comments

Base data: types uniquely lacked a comment; items on one line; distinguish unknowns
Dex entries: don't imply that pointers don't exist

data/pokemon/dex_entries/shellder.asm

@@ -1,10 +1,10 @@
-; ShellderPokedexEntry: ; 0x1b8a68
 	db "BIVALVE@" ; species name
 	dw 100, 90 ; height, weight
 
 	db   "Clamping on to an"
 	next "opponent reveals"
 	next "its vulnerable"
+
 	page "parts, so it uses"
 	next "this move only as"
 	next "a last resort.@"