### 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
- Runs C(apt-get install python-apt) for Python 2, and C(apt-get install python3-apt) for Python 3.
            - Only works with the system Python 2 or Python 3. If you are using a Python on the remote that is not
               the system Python, set I(install_python_apt=false) and ensure that the Python apt library
               for your Python version is installed some other way.
        type: bool
        default: true
author:
- Alexander Saltanov (@sashka)
version_added: "0.7"
requirements:
   - python-apt (python 2)
   - python3-apt (python 3)
   - apt-key or gpg
'''
EXAMPLES = '''
- name: Add specified repository into sources list
  ansible.builtin.apt_repository:
    repo: deb http://archive.canonical.com/ubuntu hardy partner
    state: present
- name: Add specified repository into sources list using specified filename
  ansible.builtin.apt_repository:
    repo: deb http://dl.google.com/linux/chrome/deb/ stable main
    state: present
    filename: google-chrome
- name: Add source repository into sources list
  ansible.builtin.apt_repository:
    repo: deb-src http://archive.canonical.com/ubuntu hardy partner
    state: present
- name: Remove specified repository from sources list
  ansible.builtin.apt_repository: