docs: add a reference to template-sync tool

Author: mano-lis

symfony/index.md

@@ -239,6 +239,20 @@ For instance, go to `https://localhost/greetings.jsonld` to retrieve the list of
 Of course, you can also use your favorite HTTP client to query the API.
 We are fond of [Hoppscotch](https://hoppscotch.com), a free and open source API client with good support of API Platform.
 
+## Update Your Project
+
+You have started a project with the API Platform template and you would like to benefit from the latest enhancements introduced since you created your project (i.e. [FrankenPHP](https://frankenphp.dev/). Juste use this git based tool
+[The *template-sync* project](https://github.com/coopTilleuls/template-sync) got you covered.
+
+Run the following command to import the changes since your last update:
+
+```console
+curl -sSL https://raw.githubusercontent.com/mano-lis/template-sync/main/template-sync.sh | sh -s -- https://github.com/api-platform/api-platform
+```
+Resolve potential conflicts, run `git cherry-pick --continue` and you are done!
+
+[Full documentation](https://github.com/coopTilleuls/template-sync/blob/main/README.md)
+
 ## Bringing your Own Model
 
 Your API Platform project is now 100% functional. Let's expose our own data model.