Backport #12712 to branch/v9 (#12881)

* Hide Cloud links/pages based on scope

See #11383

Help ensure that no visitor to the Teleport docs site sees content that
is irrelevant to their scope (e.g., Cloud, Open Source, or Enterprise) by
hiding scope-irrelevant content from the navigation menu and menu
pages.

For pages that aren't step-by-step guides and are meant to convey
general information about a Teleport edition, show these pages in all
scopes so users who are curious about another scope can get the
information they need.

This PR focuses on the Cloud section.

* Respond to PR feedback

docs/config.json

@@ -829,15 +829,17 @@
         },
         {
           "title": "Getting Started",
-          "slug": "/cloud/getting-started/"
+          "slug": "/cloud/getting-started/",
+          "hideInScopes": ["oss", "enterprise"]
         },
         {
           "title": "Architecture",
           "slug": "/cloud/architecture/"
         },
         {
           "title": "Downloads",
-          "slug": "/cloud/downloads/"
+          "slug": "/cloud/downloads/",
+          "hideInScopes": ["oss", "enterprise"]
         },
         {
           "title": "FAQ",