Add deep link to agent mode docs (#55802)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: jules-p <19994093+jules-p@users.noreply.github.com>
Co-authored-by: docs-bot <77750099+docs-bot@users.noreply.github.com>

Author: 3 people

content/copilot/using-github-copilot/copilot-chat/asking-github-copilot-questions-in-your-ide.md

@@ -142,6 +142,8 @@ For more detailed instructions, see [{% data variables.product.prodname_copilot_
 1. Submit a prompt. In response to your prompt, {% data variables.product.prodname_copilot_short %} streams the edits in the editor, updates the working set, and if necessary, suggests terminal commands to run.
 1. Review the changes. If {% data variables.product.prodname_copilot_short %} suggested terminal commands, confirm whether or not {% data variables.product.prodname_copilot_short %} can run them. In response, {% data variables.product.prodname_copilot_short %} iterates and performs additional actions to complete the task in your original prompt.
 
+You can also directly [open agent mode in {% data variables.product.prodname_vscode_shortname %}](vscode://GitHub.Copilot-Chat/chat?mode=agent). <!-- markdownlint-disable-line GHD003 -->
+
 For more information, see [{% data variables.product.prodname_copilot_edits_short %}](https://aka.ms/vscode-copilot-agent) in the {% data variables.product.prodname_vscode %} documentation.
 
 {% data reusables.copilot.copilot-edits.agent-mode-requests %}