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/paras.asm

@@ -0,0 +1,10 @@
+; ParasPokedexEntry: ; 0x18297f
+	db "MUSHROOM@" ; species name
+	dw 100, 120 ; height, weight
+
+	db   "The tochukaso"
+	next "growing on this"
+	next "#MON's back"
+	page "orders it to"
+	next "extract juice from"
+	next "tree trunks.@"