Document GitHub app credentials GitHub Enterprise Base URL when creating repository.

Add CLI command to Add a private Git repository on GitHub Enterprise and update instruction.

Resolves: argoproj#22389
Signed-off-by: Denis Karpelevich <[email protected]>

Author: dkarpele

docs/user-guide/private-repositories.md

@@ -113,19 +113,25 @@ Private repositories that are hosted on GitHub.com or GitHub Enterprise can be a
 
 You can configure access to your Git repository hosted by GitHub.com or GitHub Enterprise using the GitHub App method by either using the CLI or the UI.
 
-Using the CLI:
+Add a private Git repository on GitHub.com using the CLI:
 
 ```
 argocd repo add https://github.com/argoproj/argocd-example-apps.git --github-app-id 1 --github-app-installation-id 2 --github-app-private-key-path test.private-key.pem
 ```
 
+Add a private Git repository on GitHub Enterprise using the CLI:
+
+```
+argocd repo add https://ghe.example.com/repos/repo --github-app-id 1 --github-app-installation-id 2 --github-app-private-key-path test.private-key.pem --github-app-enterprise-base-url https://ghe.example.com/api/v3
+```
+
 Using the UI:
 
 1. Navigate to `Settings/Repositories`
 
     ![connect repo overview](../assets/repo-add-overview.png)
 
-2. Click `Connect Repo using GitHub App` button, enter the URL, App Id, Installation Id, and the app's private key.
+2. Click `Connect Repo using GitHub App` button, choose type: `GitHub` or `GitHub Enterprise`, enter the URL, GitHub Enterprise Base URL, App Id, Installation Id, and the app's private key.
 
     ![connect repo](../assets/repo-add-github-app.png)