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/sunflora.asm

@@ -0,0 +1,10 @@
+; SunfloraPokedexEntry: ; 0x1cdaef
+	db "SUN@" ; species name
+	dw 207, 190 ; height, weight
+
+	db   "As the hot season"
+	next "approaches, the"
+	next "petals on this"
+	page "#MON's face"
+	next "become more vivid"
+	next "and lively.@"