### Summary

Page https://docs.ansible.com/ansible/latest/cli/ansible.html and also `ansible --help` says this:
```
-a <MODULE_ARGS>, --args <MODULE_ARGS>

    module arguments
```
It does not say anything about format <MODULE_ARGS> and thus is not useful to a causal user.

I've learned how to use this parametr only from https://gist.github.com/YumaInaura/06e080e3f807338c122837bdb2d34571

### Issue Type

Documentation Report

### Component Name

https://docs.ansible.com/ansible/latest/cli/ansible.html

### Ansible Version

```console
$ ansible --version
ansible 2.10.8
```


### Configuration

```console
Not applicable.
```


### OS / Environment

Not applicable.

### Additional Information

BTW I could not find where CLI docs are stored and/or generated, which might potentially help me or other people to submit simple MRs with fixes for similarly simple doc issues. I've looked into https://docs.ansible.com/ansible/latest/dev_guide/index.html and searched for all instances of "doc" but none of occurrences refer to CLI tools.

### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
check_raw = context.CLIARGS['module_name'] in C.MODULE_REQUIRE_ARGS
        mytask = {'action': {'module': context.CLIARGS['module_name'], 'args': parse_kv(context.CLIARGS['module_args'], check_raw=check_raw)},
                  'timeout': context.CLIARGS['task_timeout']}
        
        if context.CLIARGS['module_name'] not in C._ACTION_ALL_INCLUDE_ROLE_TASKS and any(frozenset((async_val, poll))):
            mytask['async_val'] = async_val
            mytask['poll'] = poll
        return dict(
            name="Ansible Ad-Hoc",
            hosts=pattern,
            gather_facts='no',
            tasks=[mytask])
    def run(self):
        ''' create and execute the single task playbook '''
        super(AdHocCLI, self).run()
        
        pattern = to_text(context.CLIARGS['args'], errors='surrogate_or_strict')
        sshpass = None
        becomepass = None
        (sshpass, becomepass) = self.ask_passwords()
        passwords = {'conn_pass': sshpass, 'become_pass': becomepass}
        
        loader, inventory, variable_manager = self._play_prereqs()
        try:
            hosts = self.get_host_list(inventory, context.CLIARGS['subset'], pattern)
        except AnsibleError:
            if context.CLIARGS['subset']:
                raise
            else: