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/trainers/parties.asm

@@ -82,7 +82,7 @@ BugCatcherData:
 ; Viridian Forest
 	db 6, WEEDLE, CATERPIE, 0
 	db 7, CATERPIE, KAKUNA, PARA, 0
-	db 9, WEEDLE, PARA, 0
+	db 9, WEEDLE, VENONAT, 0
 ; Route 3
 	db 10, CATERPIE, WEEDLE, PARA, 0
 	db 9, WEEDLE, KAKUNA, CATERPIE, METAPOD, 0