URL in description and README broken

The URL in the repository description and the one in the README are pointing to githubschool's copy of the game instead of yours.

Please fix both so they point to your copy of the game at https://githubschool.github.io/github-games-mckittsc/

Update the URL in the README and the repository description. Start by checking both existing links against the issue text. Done means both point to https://githubschool.github.io/github-games-mckittsc/; no test file is mentioned, so verify the rendered README and repository header manually.

Rédigé par le modèle d'indexation à partir du texte de l'issue.