move faq and issues to main node

Author: duongau

articles/firewall/toc.yml

@@ -11,6 +11,10 @@ items:
     href: choose-firewall-sku.md
   - name: Preview features
     href: firewall-preview.md
+  - name: FAQ
+    href: firewall-faq.yml
+  - name: Known issues and limitations
+    href: firewall-known-issues.md
 - name: Design & architecture
   items:
   - name: Policy 
@@ -228,10 +232,6 @@ items:
     href: monitor-firewall-reference.md
 - name: Resources
   items:
-  - name: FAQ
-    href: firewall-faq.yml
-  - name: Known issues and limitations
-    href: firewall-known-issues.md
   - name: Author templates
     href: ../azure-resource-manager/templates/syntax.md
   - name: Community templates