### 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
'''
        Wrapper for `apt_pkg` module for running with Python 2.5
        '''
        try:
            result = apt_pkg.config.find_file(filespec)
        except AttributeError:
            result = apt_pkg.Config.FindFile(filespec)
        return result
    @staticmethod
    def _apt_cfg_dir(dirspec):
        '''
        Wrapper for `apt_pkg` module for running with Python 2.5
        '''
        try:
            result = apt_pkg.config.find_dir(dirspec)
        except AttributeError:
            result = apt_pkg.Config.FindDir(dirspec)
        return result
    def load(self, file):
        group = []
        f = open(file, 'r')
        for n, line in enumerate(f):
            valid, enabled, source, comment = self._parse(line)
            group.append((n, valid, enabled, source, comment))
        self.files[file] = group
    def save(self):