adding marp theme. adding linters lesson.

GPT_PROJET/mini_projet.md

Makefile

...tation/The Pragmatic Programmer Quick Reference Guide.pdf

linters/3-linters.md

linters/exercice-2/.php-cs-fixer.php

linters/exercice-2/pre-commit

linters/images/background-home.png

linters/images/ci-checks.png

linters/images/leader-board-homepage.png

linters/images/logo.png

theme/hero-background-exercice.jpg

theme/hero-background.jpg

theme/univ-lorraine.css