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/persian.asm

@@ -0,0 +1,10 @@
+; PersianPokedexEntry: ; 0x182c78
+	db "CLASSY CAT@" ; species name
+	dw 303, 710 ; height, weight
+
+	db   "Behind its lithe,"
+	next "elegant appearance"
+	next "lies a barbaric"
+	page "side. It will tear"
+	next "apart its prey on"
+	next "a mere whim.@"