feat: added starred indicator to messages (#501)

Co-authored-by: Pedro S. Lopez <pedroslopez@me.com>

index.d.ts

@@ -481,6 +481,8 @@ declare namespace WAWebJS {
         id: MessageId,
         /** Indicates if the message was forwarded */
         isForwarded: boolean,
+        /** Indicates if the message was starred */
+        isStarred: boolean,
         /** Location information contained in the message, if the message is type "location" */
         location: Location,
         /** List of vCards contained in the message */