Add portal troubleshooting instructions

Summary: Adds an internal section for portal troubleshooting

Reviewed By: passy

Differential Revision: D26847795

fbshipit-source-id: b12bef20b2f832c4264cfd5cafcced414575b82b

docs/troubleshooting.mdx

@@ -7,6 +7,8 @@ import useBaseUrl from '@docusaurus/useBaseUrl';
 
 import InternalTroubleshooting from './fb/internal-troubleshooting.mdx';
 
+import PortalTroubleshooting from './fb/portal-troubleshooting.mdx';
+
 We hope that flipper works well out of the box, but the software is a work in progress and problems will occur. Below are some known issues and steps you can take to try to resolve them.
 
 <FbInternalOnly>
@@ -249,3 +251,11 @@ To speed up CI builds, Flipper can be disabled on CI environments by making the
     end
   end
 ```
+
+<FbInternalOnly>
+
+## Portal
+
+<PortalTroubleshooting />
+
+</FbInternalOnly>