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-dkoch18

檢查 repository 的 README 和描述，其中指出了錯誤的 URL。將兩個連結都更新為 https://githubschool.github.io/github-games-dkoch18，然後確認每個連結都指向這個遊戲的副本。

由索引模型根據 Issue 內容生成。