Add authentication and authorization

backend/karaoqueue-backend/src/interfaces/dataStoredInToken.interface.ts

@@ -0,0 +1,5 @@
+interface DataStoredInToken {
+    _id: string;
+}
+
+export default DataStoredInToken;

backend/karaoqueue-backend/src/interfaces/user.interface.ts

@@ -0,0 +1,6 @@
+interface User {
+    username: string;
+    password: string;
+}
+
+export default User;