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-Matthew-Mallimo/

更新仓库描述和 README，使两者都使用 https://githubschool.github.io/github-games-Matthew-Mallimo/，而不是 githubschool 的副本 URL。检查 README 和仓库页面，然后确认两个链接都指向此仓库的游戏。

由索引模型根据 Issue 内容生成。