Automatic audio duration fetch

src/WAConnection/Constants.ts

@@ -333,6 +333,8 @@ export interface MessageOptions {
     uploadAgent?: Agent
     /** If set to true (default), automatically detects if you're sending a link & attaches the preview*/
     detectLinks?: boolean
+    /** Optionally specify the duration of the media (audio/video) in seconds */
+    duration?: number
     /** Fetches new media options for every media file */
     forceNewMediaOptions?: boolean
 }