implemented first /sample methods

src/models/note_field.ts

@@ -0,0 +1,8 @@
+import mongoose from 'mongoose';
+
+const NoteFieldSchema = new mongoose.Schema({
+  name: {type: String, index: {unique: true}},
+  qty: Number
+});
+
+export default mongoose.model('note_field', NoteFieldSchema);