refactor: participant router의 base endpoint 수정

app.js

@@ -49,7 +49,7 @@ app.use(
 );
 
 app.use('/meetings', meetingRouter);
-app.use('/meetings', participantRouter);
+app.use('/meetings/:meetingId/participants', participantRouter);
 
 app.use((req, res, next) => {
   const error = new Error(`There is no router. ${req.method} ${req.url}`);

routes/participant.js

@@ -6,14 +6,14 @@ const {
   getParticipantExistence,
 } = require('../controllers/participant');
 
-const router = express.Router();
+const router = express.Router({ mergeParams: true });
 
-router.post('/:meetingId/participants', createParticipant);
+router.post('/', createParticipant);
 
-router.get('/:meetingId/participants', getParticipantByName);
+router.get('/', getParticipantByName);
 
-router.get('/:meetingId/participants/:participantId', getParticipantById);
+router.get('/:participantId', getParticipantById);
 
-router.get('/:meetingId/participants/existence', getParticipantExistence);
+router.get('/existence', getParticipantExistence);
 
 module.exports = router;