##### 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')
```
''' pipe text through a pager '''
        if 'LESS' not in os.environ:
            os.environ['LESS'] = CLI.LESS_OPTS
        try:
            cmd = subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE, stdout=sys.stdout)
            cmd.communicate(input=to_bytes(text))
        except IOError:
            pass
        except KeyboardInterrupt:
            pass
    @classmethod
    def tty_ify(cls, text):
        t = cls._ITALIC.sub("`" + r"\1" + "'", text)    
        t = cls._BOLD.sub("*" + r"\1" + "*", t)         
        t = cls._MODULE.sub("[" + r"\1" + "]", t)       
        t = cls._URL.sub(r"\1", t)                      
        t = cls._CONST.sub("`" + r"\1" + "'", t)        
        return t
    @staticmethod
    def _play_prereqs():