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-silbermm

更新 README 中的 URL 和仓库描述，它们目前指向 GitHub School 的副本。验证两个链接都指向 https://githubschool.github.io/github-games-silbermm，并确认 README 渲染出更正后的目标地址。

由索引模型根据 Issue 内容生成。