##### SUMMARY
With the introduction of `Collection` mechanism using the `ansible-galaxy` CLI, the command and sub command help texts should be reflecting the new feature. The CLI currently validates the `collection` sub-command but the help text is still saying `role` is the only valid sub-command.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
`ansible-galaxy`

##### ANSIBLE VERSION
```
ansible 2.9.7
  config file = /etc/ansible/ansible.cfg
  configured module search path = ['/home/dvercill/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/dvercill/.local/lib/python3.8/site-packages/ansible
  executable location = /home/dvercill/.local/bin/ansible
  python version = 3.8.2 (default, Feb 28 2020, 00:00:00) [GCC 10.0.1 20200216 (Red Hat 10.0.1-0.8)]
```

##### CONFIGURATION
N/A

##### OS / ENVIRONMENT
Fedora Workstation 32 beta

##### STEPS TO REPRODUCE
```
$ ansible-galaxy doesnotexist
usage: ansible-galaxy role [-h] ROLE_ACTION ...
ansible-galaxy role: error: argument ROLE_ACTION: invalid choice: 'doesnotexist' (choose from 'init', 'remove', 'delete', 'list', 'search', 'import', 'setup', 'login', 'info', 'install')
```
"""Run the ansible command
        Subclasses must implement this method.  It does the actual work of
        running an Ansible command.
        """
        self.parse()
        display.vv(to_text(opt_help.version(self.parser.prog)))
        if C.CONFIG_FILE:
            display.v(u"Using %s as config file" % to_text(C.CONFIG_FILE))
        else:
            display.v(u"No config file found; using defaults")
        
        for deprecated in C.config.DEPRECATED:
            name = deprecated[0]
            why = deprecated[1]['why']
            if 'alternatives' in deprecated[1]:
                alt = ', use %s instead' % deprecated[1]['alternatives']
            else:
                alt = ''
            ver = deprecated[1]['version']
            display.deprecated("%s option, %s %s" % (name, why, alt), version=ver)
    @staticmethod
    def split_vault_id(vault_id):