Add reproducible example for php image with gettext ready to roll #5

Each time I setup a new stack based on php, I struggle massively to get the gettext integration to work. Currently, I'm back at it again, as this is the first time I setup a php stack with a separate apache and php container (php running as separate php-fpm container).

The current state (solved now) is pretty much detailed here: Cannot get gettext to work in php:fpm-8.2 Docker Container.

Given the abundant amount of questions online in so many forums about the 'gettext not working with php' problem, while it is still the first translation tool of choice for PHP stacks; could you maybe add some instructions about e.g. how you would add the gettext extension in a way that actually works? Kind of like the little and short but precise infos about how to setup SSL on an apache container, which was very helpful for that.