feat: add AvailableModels export to sttDefaults and update index file

Author: jakmro

packages/react-native-executorch/src/constants/sttDefaults.ts

@@ -78,3 +78,5 @@ export enum STREAMING_ACTION {
   DATA,
   STOP,
 }
+
+export { AvailableModels };

packages/react-native-executorch/src/index.tsx

@@ -86,4 +86,8 @@ export { SpeechToTextLanguage };
 export * from './constants/modelUrls';
 export * from './constants/ocr/models';
 export * from './constants/llmDefaults';
-export { STREAMING_ACTION, MODES } from './constants/sttDefaults';
+export {
+  STREAMING_ACTION,
+  MODES,
+  AvailableModels,
+} from './constants/sttDefaults';