message: docs: improve grammer in CLI command template
  Before
  ```
  This command has the following commands:
  ```
  Now
  ```
  This command has the following sub-commands:
  ```
  PR Close
diff: {% endif%}
  {% if doc.subcommands.length %}
  - <p>This command has the following <a href="#{$ doc.name $}-commands">commands</a>:<p>
  + <p>This command has the following <a href="#{$ doc.name $}-commands">sub-commands</a>:<p>
  <ul>
  {% for subcommand in doc.subcommands %}
  <li><a class="code-anchor" href="#{$ subcommand.name $}-command">{$ subcommand.name $}</a></li>
  