docs: add migration guide (#5439)

Co-authored-by: Fernandez Ludovic <[email protected]>

Author: alexandear

docs/src/config/sidebar.yml

@@ -28,6 +28,8 @@
       link: "/product/thanks/"
     - label: "Changelog"
       link: "/product/changelog/"
+    - label: "Migration Guide"
+      link: "/product/migration-guide/"
     - label: "Roadmap"
       link: "/product/roadmap/"
     - label: "Performance"
@@ -56,4 +58,3 @@
       link: /plugins/module-plugins/
     - label: Go Plugin System
       link: /plugins/go-plugins/
-