Feature/tutorials breadcrumbs (#368)

# Description of change

Adds breadcrumbs on tutorials pages

![image](https://github.com/user-attachments/assets/e815bf46-66cd-49bc-bbaf-eea249fe9a8d)


## Type of change

Select the type of change that you're making:

- [ ] Bug fix (Addresses an issue in existing content such as a typo)
- [x] Enhancement (Adds new content)

## Open Questions and Pre-Merge TODOs
- [ ] Use github checklists to create a list. When an item is solved,
check the box and explain the answer.

tutorials/antora.yml

@@ -1,3 +1,5 @@
 name: tutorials
 title: Tutorials
 version: ~
+nav:
+  - modules/ROOT/nav.adoc

tutorials/modules/ROOT/nav.adoc

@@ -0,0 +1,4 @@
+.Tutorials
+* xref:ROOT:user-code-namespaces.adoc
+* xref:ROOT:sql-gen-data.adoc
+// you don't need to add all existing docs here, if you add at least one, breadcrumbs appear...