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-rg026287

Update the URL in the repository description and in the README. Use the target URL provided in the issue, then verify that both locations point to the repository's copy of the game. No tests are mentioned; completion is confirmed when both links use the specified URL.

索引モデルが issue の本文から書いたものです。