feat: split metadata into smal pieces

Reviewed-by: Hasko, Vladimir <vladimir.hasko@t-systems.com>
Co-authored-by: gtema <artem.goncharov@gmail.com>
Co-committed-by: gtema <artem.goncharov@gmail.com>

otc_metadata/data/documents/iam-umn.yaml

@@ -0,0 +1,9 @@
+---
+hc_location: usermanual/iam
+html_location: docs/iam/umn
+link: /identity-access-management/umn/
+pdf_name: iam-umn
+rst_location: umn/source
+service_type: iam
+title: User Guide
+type: umn