URL in description and README broken

The URL in the repository description and 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-hj8642/

Check the repository description and README, which are the two locations named in the issue. Replace the incorrect game URL in both with https://githubschool.github.io/github-games-hj8642/ and verify that each link points to the repository's copy.

索引モデルが issue の本文から書いたものです。