move dev-guides into doc folder and rename the doc-type accordingly (#62)

Reviewed-on: #62
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/documents/dms-dev.yaml

@@ -2,10 +2,10 @@
 hc_location: devg/dms
 html_location: docs/dms/dev
 link: /distributed-message-service/dev-guide/
-rst_location: dev_guide/source
+rst_location: doc/dev-guide/source
 service_type: dms
 title: Developer Guide
-type: dev
+type: dev-guide
 cloud_environments:
   - name: eu_de
     visibility: public