add update post endpoint

routes/post.js

@@ -240,6 +240,21 @@ DB.getDB.then((DB) => {
         });
     });
 
+    router.post("/:id", async (req, res) => {
+        const profileid = getProfileId(req) + '';
+        const postId = req.params.id;
+        const post = await DB.getPost(postId);
+        const newContent = req.body.content;
+        if (!postBelongToProfile(post, profileid))
+            return res.json({
+                status: "This post is not yours."
+            });
+        await DB.updatePost(postId, newContent, post.content);
+        return res.json({
+            status: "ok"
+        });
+    });
+
 });
 
 module.exports = router