update appsettings example

AuctionTracker/appsettings.json.example

   "blizzardApiKey": "your_api_key",
   "pushoverSecretKey": "your_secret_key",
   "pushoverUserKey": "your_public_key"
+  "locale": "en_GB",
+  "character": "your_char_name",
+  "realm": "your_realm_name"
 }