Copilot CLI: Document the skill subcommand (#61972)

Author: hubwriter

content/copilot/how-tos/copilot-cli/customize-copilot/add-skills.md

@@ -53,6 +53,8 @@ Use the /frontend-design skill to create a responsive navigation bar in React.
 
 * **Remove skills:** to remove a skill that you have added directly—not via a plugin—use the command `/skills remove SKILL-DIRECTORY`. To remove skills added as part of a plugin you must manage the plugin itself. Use the `info` subcommand to find out which plugin a skill came from.
 
+The `/skills` commands above run inside an interactive session. The same list, add, and remove operations are also available from the terminal command line by using the `copilot skill` subcommand. This is useful for scripting or for setting up skills before you start a session. For example, run `copilot skill list` to list your skills, or `copilot skill add <FILE | URL | DIRECTORY>` to add one. For the full set of subcommands for {% data variables.copilot.copilot_cli_short %}, see [AUTOTITLE](/copilot/reference/copilot-cli-reference/cli-command-reference).
+
 {% data reusables.copilot.skills-compared %}
 
 To learn more about how skills differ from other customization features, see [AUTOTITLE](/copilot/concepts/agents/copilot-cli/comparing-cli-features).

content/copilot/reference/copilot-cli-reference/cli-command-reference.md

@@ -26,6 +26,7 @@ docsTeamMetrics:
 | `copilot login` [OPTION] | Authenticate with {% data variables.product.prodname_copilot_short %} via the OAuth device flow. See [`copilot login` options](#copilot-login-options). |
 | `copilot mcp`          | Manage MCP server configurations from the command line. |
 | `copilot plugin`       | Manage plugins and plugin marketplaces.            |
+| `copilot skill`        | Manage agent skills from the command line (list, add, and remove skills). See [AUTOTITLE](/copilot/how-tos/copilot-cli/customize-copilot/add-skills). |
 | `copilot update`       | Download and install the latest version.           |
 | `copilot version`      | Display version information and check for updates. |