### Summary

The [`filename` parameter docs](https://docs.ansible.com/ansible/latest/collections/ansible/builtin/apt_repository_module.html#parameter-filename) don't give enough info to tell how the file name is generated.

I believe my `repo: deb https://packagecloud.io/linz/prod/ubuntu/ {{ ansible_distribution_release }} main` is hanging indefinitely ~~, and I suspect this has something to do with the file name being a duplicate, resulting in a background prompt which is never printed or dismissed, but it's hard to tell based on the [code](https://github.com/ansible/ansible/blob/f3be331c9cb2f2c6edeb0bdf28a1e8a9681d727c/lib/ansible/modules/apt_repository.py#L235-L258)~~ (Based on copying the code into a Python interpreter it looks like the generated file name is `packagecloud_io_linz_prod_ubuntu.list`, which looks fine.).

### Issue Type

Documentation Report

### Component Name

lib/ansible/modules/apt_repository.py

### Ansible Version

```console
N/A
```


### Configuration

```console
N/A
```


### OS / Environment

N/A

### Additional Information

N/A

### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
apt_pkg_name = 'python3-apt' if PY3 else 'python-apt'
        if has_respawned():
            
            module.fail_json(msg="{0} must be installed and visible from {1}.".format(apt_pkg_name, sys.executable))
        interpreters = ['/usr/bin/python3', '/usr/bin/python2', '/usr/bin/python']
        interpreter = probe_interpreters_for_module(interpreters, 'apt')
        if interpreter:
            
            respawn_module(interpreter)
            
        
        if module.check_mode:
            module.fail_json(msg="%s must be installed to use check mode. "
                                 "If run normally this module can auto-install it." % apt_pkg_name)
        if params['install_python_apt']:
            install_python_apt(module, apt_pkg_name)
        else:
            module.fail_json(msg='%s is not installed, and install_python_apt is False' % apt_pkg_name)
        
        interpreter = probe_interpreters_for_module(interpreters, 'apt')
        if interpreter:
            
            
            respawn_module(interpreter)