Add experimental support for zero-width emotes

lib/constants.dart

@@ -3,3 +3,15 @@ const clientId = String.fromEnvironment('CLIENT_ID');
 
 /// Twitch API client secret.
 const secret = String.fromEnvironment('SECRET');
+
+/// BTTV emotes with zero width to allow for overlaying other emotes.
+const zeroWidthEmotes = [
+  "SoSnowy",
+  "IceCold",
+  "SantaHat",
+  "TopHat",
+  "ReinDeer",
+  "CandyCane",
+  "cvMask",
+  "cvHazmat",
+];