Add references to the firewall requirements docs (#2815)

docs/checks/actions.md

@@ -9,6 +9,8 @@ Make sure the runner has access to actions service for GitHub.com or GitHub Ente
   - The runner needs to access `https://api.github.com` for downloading actions.
   - The runner needs to access `https://vstoken.actions.githubusercontent.com/_apis/.../` for requesting an access token.
   - The runner needs to access `https://pipelines.actions.githubusercontent.com/_apis/.../` for receiving workflow jobs.
+  ---
+  **NOTE:** for the full list of domains that are required to be in the firewall allow list refer to the [GitHub self-hosted runners requirements documentation](https://docs.github.com/en/actions/hosting-your-own-runners/managing-self-hosted-runners/about-self-hosted-runners#communication-between-self-hosted-runners-and-github).
 
   These can by tested by running the following `curl` commands from your self-hosted runner machine:
 

docs/checks/network.md

@@ -14,7 +14,7 @@
 
 - A Proxy may try to modify the HTTPS request (like add or change some http headers) and causes the request become incompatible with the Actions Service (ASP.NetCore), Ex: [Nginx](https://github.com/dotnet/aspnetcore/issues/17081)
 
-- Firewall rules that block action runner from accessing certain hosts, ex: `*.github.com`, `*.actions.githubusercontent.com`, etc
+- Firewall rules that block action runner from accessing [certain hosts](https://docs.github.com/en/actions/hosting-your-own-runners/managing-self-hosted-runners/about-self-hosted-runners#communication-between-self-hosted-runners-and-github), ex: `*.github.com`, `*.actions.githubusercontent.com`, etc
 
 
 ### Identify and solve these problems