improve DX

[oallain]

Q	A
Bug fix?	no
New feature?	yes
BC breaks?	no
Fixed issue

• [x] Add PHP 8
• [x] Add Sylius 1.10
• [x] Create a Makefile to install Sylius with Plugin
• [x] Use this Makefile in CI
• [x] Update dependencies et fix errors
• [x] Update Doc