Update part4c.md

Updated code to match previous notes application in other parts.

Author: Sam Vitare

src/content/4/en/part4c.md

@@ -433,7 +433,7 @@ notesRouter.post('/', async (request, response) => {
   user.notes = user.notes.concat(savedNote._id) //highlight-line
   await user.save()  //highlight-line
 
-  response.json(savedNote)
+  response.status(201).json(savedNote)
 })
 ```
 The note scheme will also need to change as follows in our models/note.js file: