doc/cephadm: Fix command plus improvements in service/mgmt-gateway.rst

Remove double backticks from a CLI command.

Use bash prompt consistently for CLI command blocks.

Don't capitalize word in middle of sentence.

Talk about "admin" instead of "user", similarly to the last text
paragraph in the doc.

Signed-off-by: Ville Ojamo <[email protected]>

Author: bluikko

doc/cephadm/services/mgmt-gateway.rst

@@ -74,7 +74,7 @@ run the ``mgmt-gateway`` in HA mode users can either use the cephadm command lin
 
 Or provide specification files as following:
 
-``mgmt-gateway`` Configuration:
+``mgmt-gateway`` configuration:
 
 .. code-block:: yaml
 
@@ -85,7 +85,7 @@ Or provide specification files as following:
       enable_auth: true
       virtual_ip: 192.168.100.220
 
-In addition, the user must configure an ingress service to provide virtual IP functionality for
+In addition, the admin must configure an ingress service to provide virtual IP functionality for
 the ``mgmt-gateway``. For example:
 
 .. code-block:: yaml
@@ -199,7 +199,7 @@ running daemon(s) you must redeploy the daemon(s) in order to have them actually
 
 For example:
 
-.. code-block:: bash
+.. prompt:: bash #
 
      ceph config set mgr mgr/cephadm/container_image_nginx <new-nginx-image>
-     ceph orch redeploy ``mgmt-gateway``
+     ceph orch redeploy mgmt-gateway