fix(Encounters): Add missing Route 20 flying special encounters

Add overworld-flying-special encounters for Route 20 (Charizard,
Articuno, Zapdos, Moltres, Dragonite) to match Route 19.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: DJ-Meyers

data/v2/csv/encounters.csv

@@ -64644,3 +64644,13 @@ id,version_id,location_area_id,encounter_slot_id,pokemon_id,min_level,max_level
 70201,32,833,1177,140,44,44
 70202,31,833,1177,142,44,44
 70203,32,833,1177,142,44,44
+70204,31,278,1178,6,3,56
+70205,32,278,1178,6,3,56
+70206,31,278,1178,144,3,56
+70207,32,278,1178,144,3,56
+70208,31,278,1178,145,3,56
+70209,32,278,1178,145,3,56
+70210,31,278,1178,146,3,56
+70211,32,278,1178,146,3,56
+70212,31,278,1178,149,3,56
+70213,32,278,1178,149,3,56