deleted orphaned and duplicate pages

Author: devalog

fern/products/api-def/openapi-pages/examples.mdx

@@ -25,6 +25,8 @@ navigation:
         path: ./pages/features/insights.mdx
       - page: Evaluation
         path: ./pages/features/evals.mdx
+      - page: Role-based access control
+        path: ./pages/features/rbac.mdx
       - page: Slack app
         path: ./pages/features/slack-app.mdx
   - api: API reference