Update app.js

app.js

@@ -10,7 +10,7 @@ app.get('/', (req, res) => {
   res.send('api');
 });
 
-app.get('/r18', (req, res) => {
+app.get('/mm', (req, res) => {
   const r18FolderPath = path.join(__dirname, 'api', 'mm');
   const images = fs.readdirSync(r18FolderPath);
   const randomImage = getRandomImage(images);