Copilot CLI auth: add section links to authentication method summary (#60727)

Author: hubwriter

content/copilot/how-tos/copilot-cli/set-up-copilot-cli/authenticate-copilot-cli.md

@@ -20,9 +20,9 @@ Authentication is required for any other {% data variables.copilot.copilot_cli %
 
 When authentication is required, {% data variables.copilot.copilot_cli_short %} supports three methods. The method you use depends on whether you are working interactively or in an automated environment.
 
-* **OAuth device flow**: The default and recommended method for interactive use. When you run `/login` in {% data variables.copilot.copilot_cli_short %}, the CLI generates a one-time code and directs you to authenticate in your browser. This is the simplest way to authenticate.
-* **Environment variables**: Recommended for CI/CD pipelines, containers, and non-interactive environments. You set a supported token as an environment variable (`COPILOT_GITHUB_TOKEN`, `GH_TOKEN`, or `GITHUB_TOKEN`), and the CLI uses it automatically without prompting.
-* **{% data variables.product.prodname_cli %} fallback**: If you have {% data variables.product.prodname_cli %} (`gh`) (note: the `gh` CLI, not `copilot`) installed and authenticated, {% data variables.copilot.copilot_cli_short %} can use its token automatically. This is the lowest priority method and activates only when no other credentials are found.
+* **OAuth device flow**: The default and recommended method for interactive use. When you run `/login` in {% data variables.copilot.copilot_cli_short %}, the CLI generates a one-time code and directs you to authenticate in your browser. This is the simplest way to authenticate. See [Authenticating with OAuth](#authenticating-with-oauth).
+* **Environment variables**: Recommended for CI/CD pipelines, containers, and non-interactive environments. You set a supported token as an environment variable (`COPILOT_GITHUB_TOKEN`, `GH_TOKEN`, or `GITHUB_TOKEN`), and the CLI uses it automatically without prompting. See [Authenticating with environment variables](#authenticating-with-environment-variables).
+* **{% data variables.product.prodname_cli %} fallback**: If you have {% data variables.product.prodname_cli %} (`gh`) (note: the `gh` CLI, not `copilot`) installed and authenticated, {% data variables.copilot.copilot_cli_short %} can use its token automatically. This is the lowest priority method and activates only when no other credentials are found. See [Authenticating with {% data variables.product.prodname_cli %}](#authenticating-with-github-cli).
 
 Once authenticated, {% data variables.copilot.copilot_cli_short %} remembers your login and automatically uses the token for all {% data variables.product.prodname_copilot_short %} API requests. You can log in with multiple accounts, and the CLI will remember the last-used account. Token lifetime and expiration depend on how the token was created on your account or organization settings.