add a CI to check the format of the code

[amtoine]

cc/ @atxr

about the question in #78 and the change request in #81.

@atxr, could you add a very simple CI in .github/workflows/ to ~format~ check the format of the code base with prettier? :yum:

EDIT: the CI should fail if the format is not good. the CI should not try to commit on top of a PR branch if the format is bad.

[ctmbl]

That would be sooooo cool

[amtoine]

that's a must have :+1:

[amtoine]

@atxr

i've updated the issue title and description :+1:

sorry i was in a rush yesterday... i was not clear :yum: