add blueprints docs

Reviewed-by: Gode, Sebastian <sebastian.gode@t-systems.com>
Co-authored-by: tischrei <tino.schreiber@t-systems.com>
Co-committed-by: tischrei <tino.schreiber@t-systems.com>

otc_metadata/data/services/blueprints.yaml

@@ -0,0 +1,13 @@
+---
+environment: hidden
+repositories:
+- environment: public
+  repo: opentelekomcloud-blueprints/docs
+  type: github
+service_category: other
+service_title: Blueprints
+service_type: blueprints
+service_uri: blueprints
+teams:
+- name: eco
+  permission: write