Create backend model for the user feedback.

models/feedback.js

@@ -0,0 +1,23 @@
+const mongoose = require("mongoose");
+
+const feedbackSchema = new mongoose.Schema({
+    merchant: {
+        type: mongoose.Schema.Types.ObjectId,
+        ref: "Merchant",
+        required: true
+    },
+    title: {
+        type: String,
+        required: [true, "FEEDBACK MUST CONTAIN A TITLE"]
+    },
+    contents: {
+        type: String,
+        require: [true, "MESSAGE TOO SHORT"]
+    },
+    date: {
+        type: Date,
+        required: true
+    }
+});
+
+module.exports = mongoose.model("Feedback", FeedbackSchema);