Add docker_prune sample to remove everything, including non-dangling images (#52744)
Add docker_prune sample to remove everything, including non-dangling images (#52744)

* Update docker_prune.py

##### SUMMARY
Add example to remove everything, including non-dangling images


##### ISSUE TYPE
- Docs Pull Request

+label: docsite_pr

* fix indentation

* Update lib/ansible/modules/cloud/docker/docker_prune.py

Co-Authored-By: nicosingh <59e89e9147888bb5006fab7cbed2cb88ec600467@gmail.com>

thaim/ansible,thaim/ansible