### 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
''' is an extra-simple tool/framework/API for doing 'remote things'.
        this command allows you to define and run a single task 'playbook' against a set of hosts
    '''
    def init_parser(self):
        ''' create an options parser for bin/ansible '''
        super(AdHocCLI, self).init_parser(usage='%prog <host-pattern> [options]',
                                          desc="Define and run a single task 'playbook' against"
                                          " a set of hosts",
                                          epilog="Some modules do not make sense in Ad-Hoc (include,"
                                          " meta, etc)")
        opt_help.add_runas_options(self.parser)
        opt_help.add_inventory_options(self.parser)
        opt_help.add_async_options(self.parser)
        opt_help.add_output_options(self.parser)
        opt_help.add_connect_options(self.parser)
        opt_help.add_check_options(self.parser)
        opt_help.add_runtask_options(self.parser)
        opt_help.add_vault_options(self.parser)
        opt_help.add_fork_options(self.parser)
        opt_help.add_module_options(self.parser)
        opt_help.add_basedir_options(self.parser)
        opt_help.add_tasknoplay_options(self.parser)
        
        self.parser.add_argument('-a', '--args', dest='module_args',
                                 help="module arguments", default=C.DEFAULT_MODULE_ARGS)
        self.parser.add_argument('-m', '--module-name', dest='module_name',
                                 help="module name to execute (default=%s)" % C.DEFAULT_MODULE_NAME,
                                 default=C.DEFAULT_MODULE_NAME)
        self.parser.add_argument('args', metavar='pattern', help='host pattern')
    def post_process_args(self, options):