Add reference docs for extension command group (#8577)

Also remove vestigial `-E` option in extension guide.

Author: scotttrinh

docs/reference/datamodel/extensions.rst

@@ -53,8 +53,7 @@ Standalone extensions
 
 .. api-index:: postgis
 
-Additionally, standalone extension packages can be installed via the CLI,
-with ``postgis`` being a notable example.
+Additionally, standalone extension packages can be installed on local project-managed instances via the CLI, with ``postgis`` being a notable example.
 
 List installed extensions:
 
@@ -79,7 +78,7 @@ Install the ``postgis`` extension:
 
 .. code-block:: bash
 
-  $ gel extension install -E postgis
+  $ gel extension install postgis
   Found extension package: postgis version 3.4.3+6b82d77
   00:00:03 [====================] 22.49 MiB/22.49 MiB
   Extension 'postgis' installed successfully.

docs/reference/using/cli/gel_extension/index.rst

@@ -0,0 +1,33 @@
+.. _ref_cli_gel_extension:
+
+=============
+gel extension
+=============
+
+The :gelcmd:`extension` command group contains commands for managing standalone extensions.
+
+.. toctree::
+   :maxdepth: 2
+   :hidden:
+
+   list
+   list-available
+   install
+   uninstall
+
+Subcommands
+===========
+
+.. list-table::
+   :class: synopsis
+
+   * - :ref:`ref_cli_gel_extension_list`
+     - List installed extensions.
+   * - :ref:`ref_cli_gel_extension_list_available`
+     - List available extensions.
+   * - :ref:`ref_cli_gel_extension_install`
+     - Install an extension.
+   * - :ref:`ref_cli_gel_extension_uninstall`
+     - Uninstall an extension.
+
+See :ref:`Connection options <ref_cli_gel_connopts>` for options applicable to all subcommands.

docs/reference/using/cli/gel_extension/install.rst

@@ -0,0 +1,34 @@
+.. _ref_cli_gel_extension_install:
+
+=====================
+gel extension install
+=====================
+
+Install an extension.
+
+.. cli:synopsis::
+
+  gel extension install <extension> [<options>]
+
+Arguments
+=========
+
+:cli:synopsis:`<extension>`
+    The name of the extension to install.
+
+Options
+=======
+
+See :ref:`Connection options <ref_cli_gel_connopts>` for global options.
+
+Examples
+========
+
+Install the ``postgis`` extension:
+
+.. code-block:: bash
+
+  $ gel extension install postgis
+  Found extension package: postgis version 3.4.3+6b82d77
+  00:00:03 [====================] 22.49 MiB/22.49 MiB
+  Extension 'postgis' installed successfully.

docs/reference/using/cli/gel_extension/list-available.rst

@@ -0,0 +1,27 @@
+.. _ref_cli_gel_extension_list_available:
+
+============================
+gel extension list-available
+============================
+
+List available extensions.
+
+.. cli:synopsis::
+
+  gel extension list-available [<options>]
+
+Options
+=======
+
+See :ref:`Connection options <ref_cli_gel_connopts>` for global options.
+
+Examples
+========
+
+.. code-block:: bash
+
+  $ gel extension list-available
+  ┌─────────┬───────────────┐
+  │ Name    │ Version       │
+  │ postgis │ 3.4.3+6b82d77 │
+  └─────────┴───────────────┘

docs/reference/using/cli/gel_extension/list.rst

@@ -0,0 +1,27 @@
+.. _ref_cli_gel_extension_list:
+
+==================
+gel extension list
+==================
+
+List installed extensions.
+
+.. cli:synopsis::
+
+  gel extension list [<options>]
+
+Options
+=======
+
+See :ref:`Connection options <ref_cli_gel_connopts>` for global options.
+
+Examples
+========
+
+.. code-block:: bash
+
+  $ gel extension list
+  ┌─────────┬───────────────┐
+  │ Name    │ Version       │
+  │ postgis │ 3.4.3+6b82d77 │
+  └─────────┴───────────────┘

docs/reference/using/cli/gel_extension/uninstall.rst

@@ -0,0 +1,32 @@
+.. _ref_cli_gel_extension_uninstall:
+
+=======================
+gel extension uninstall
+=======================
+
+Uninstall an extension.
+
+.. cli:synopsis::
+
+  gel extension uninstall <extension> [<options>]
+
+Arguments
+=========
+
+:cli:synopsis:`<extension>`
+    The name of the extension to uninstall.
+
+Options
+=======
+
+See :ref:`Connection options <ref_cli_gel_connopts>` for global options.
+
+Examples
+========
+
+Uninstall the ``postgis`` extension:
+
+.. code-block:: bash
+
+  $ gel extension uninstall postgis
+  Extension 'postgis' uninstalled successfully.

docs/reference/using/cli/index.rst

@@ -151,6 +151,7 @@ The ``cli.toml`` has the following structure. All fields are optional:
     gel_list
     gel_info
     gel_cli_upgrade
+    gel_extension/index
     gel_server/index
     gel_describe/index
     gel_instance/index