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/pidgeotto.asm

@@ -1,10 +1,10 @@
-; PidgeottoPokedexEntry: ; 0x181d75
 	db "BIRD@" ; species name
 	dw 307, 660 ; height, weight
 
 	db   "It slowly flies in"
 	next "a circular pat-"
 	next "tern, all the"
+
 	page "while keeping a"
 	next "sharp lookout for"
 	next "prey.@"