feat: refactor quest models

+ separate stage and exception
+ reuse commandResponder

packages/models/requirement.js

@@ -0,0 +1,12 @@
+import { Schema } from 'mongoose'
+
+const requirementSchema = new Schema({
+  requirements: [
+    {
+      type: String,
+      required: true,
+    },
+  ],
+})
+
+export default requirementSchema