fix: Made it clear in the document about the different between etcd storage formate and etcd versioning

Author: wendy-ha18

content/en/docs/v3.4/how-to-migrate.md

@@ -1,11 +1,15 @@
 ---
 title: How to migrate etcd from v2store to v3store
-description: etcd v2 to v3 migration guide
+description: etcd v2store to v3store migration guide
 weight: 1200
 ---
 
 `migrate` to transform etcd v2store to v3store.
 
+Learn more about the difference between the [etcd data storage format](https://etcd.io/docs/v3.6/learning/data_model/) and the [etcd versioning](https://etcd.io/docs/v3.6/op-guide/versioning/).
+
+This document focus on how to migrate existing data from the v2store to the v3store. For a detailed guideline of migrating from API v2 to API v3, please refer to [Migrate applications from using API v2 to API v3](https://etcd.io/docs/v3.4/op-guide/v2-migration/).
+
 {{% alert color="warning" %}}
 ⚠️ **Deprecated functionality:**