feat(Countries): Adding countries endpoint

lib/Models/meta-data.model.js

@@ -0,0 +1,10 @@
+const mongoose = require('mongoose');
+const { Schema } = mongoose;
+
+const schema = new Schema({
+    meta_group: { type: Schema.Types.ObjectId, ref: 'metagroups'},// settings, terms, collaborator
+    meta_key: { type: String, required: true }, // collaborator
+    meta_value: { type: String }
+});
+
+module.exports = mongoose.model( "metadatas", schema );