Add section on updating Copilot CLI

Author: kaviraj07

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

@@ -111,6 +111,12 @@ You can download the executables directly from [the `copilot-cli` repository](ht
 
 Download the executable for your platform, unpack it, and run.
 
+## Updating {% data variables.copilot.copilot_cli_short %}
+
+Once {% data variables.copilot.copilot_cli_short %} is installed, you can update it to the latest version by running `/update` inside an active session, or `copilot update` from your shell. Either method updates your installation in place, so you don't need to rerun the original install command for your package manager.
+
+For all available commands, see [AUTOTITLE](/copilot/reference/copilot-cli-reference/cli-command-reference).
+
 ## Authenticating with {% data variables.copilot.copilot_cli_short %}
 
 On first launch, if you're not currently logged in to {% data variables.product.github %}, you'll be prompted to use the `/login` slash command. Enter this command and follow the on-screen instructions to authenticate. For more information on the authentication process, see [AUTOTITLE](/copilot/how-tos/copilot-cli/set-up-copilot-cli/authenticate-copilot-cli).