Viridian Forest & Route 24-25 tweaks

This reduces the amount of Para present in the early-game; my playtest had me feel that there were a few too many.

So what I did here was;
- Replace an encounter entry with Pidgey, which was seen in Yellow. Additionally, I replaced the Butterfree with the popular L9 Pidgeotto, which to me makes a lot more sense. You should grind for Butterfree.
- The end trainer uses a Venonat, a Pokemon I think we could feature more early-game (like in Yellow again)

Additionally, I also tweaked Route 24-25 to have the early Venonat like Yellow does. This ensures the Yellow learnset changes come into play. I also added Pidgeotto back here over the Butterfree, I still don't think it should be available this immediately...

data/wild/maps/Route24.asm

@@ -4,7 +4,7 @@ Route24WildMons:
 	db 12, ODDISH
 	db 12, PIDGEY
 	db 12, ODDISH
-	db 13, ODDISH
+	db 13, VENONAT
 	db 10, ABRA
 	db 14, BELLSPROUT
 	db 13, PIDGEY