Use IA to generate PHPDoc

Mission Quality 🚀

This MR proposes to add a new util command to the ACSEO Makefile in order to automate the generation of PHPDoc.

it relies on a Docker image (https://hub.docker.com/repository/docker/acseo/ai-phpdoc/) and doesn't requires any new dependencies on the local machine.

if the OPENAI_KEY is not present in a .env file, the command will do nothing (and does not trigger any error)