Add environment filter to services_by_category

otc_metadata/data/documents/apig-dev.yaml

@@ -1,5 +1,4 @@
 ---
-environment: hidden
 hc_location: devg/apig
 html_location: docs/apig/dev
 link: /api-gateway/dev-guide/

otc_metadata/data/documents/hss-api-ref.yaml

@@ -1,5 +1,6 @@
 ---
 hc_location: api/hss2.0
+environment: internal
 html_location: docs/hss/api-ref
 link: /host-security-service/api-ref/
 pdf_name: hss-api-ref

otc_metadata/data/documents/hss-umn.yaml

@@ -1,5 +1,6 @@
 ---
 hc_location: usermanual/hss2.0
+environment: internal
 html_location: docs/hss/umn
 link: /host-security-service/umn/
 pdf_name: hss-umn

otc_metadata/data/services/hss.yaml

@@ -1,5 +1,5 @@
 ---
-environment: public
+environment: internal
 repositories:
 - environment: internal
   repo: docs/host-security-service