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/raticate.asm

@@ -0,0 +1,10 @@
+; RaticatePokedexEntry: ; 0x181ea3
+	db "RAT@" ; species name
+	dw 204, 410 ; height, weight
+
+	db   "The webs on its"
+	next "hind legs enable"
+	next "it to cross"
+	page "rivers. It search-"
+	next "es wide areas for"
+	next "food.@"