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/ViridianForest.asm

@@ -3,13 +3,13 @@ ViridianForestWildMons:
 	db  6, CATERPIE
 	db  6, WEEDLE
 	db  6, CATERPIE
-	db  5, PARA
+	db  5, PIDGEY
 	db  6, MONJA
 	db  6, PARA
 	db  8, KAKUNA
 	db  8, METAPOD
 	db  5, PIKACHU
-	db 10, BUTTERFREE
+	db 9, PIDGEOTTO
 	end_grass_wildmons
 
 	def_water_wildmons 0 ; encounter rate