Rename all files in data/pokedex/entries/

Some people suggested this would be a good idea, and make management of
the files easier. I'm inclined to agree.

data/pokedex/entries/weezing.asm

@@ -0,0 +1,10 @@
+; WeezingPokedexEntry: ; 0x1b92ec
+	db "POISON GAS@" ; species name
+	dw 311, 210 ; height, weight
+
+	db   "When it inhales"
+	next "poisonous gases"
+	next "from garbage, its"
+	page "body expands, and"
+	next "its insides smell"
+	next "much worse.@"