Support Cloudflare-style resolution

https://developers.cloudflare.com/pages/configuration/serving-pages/#route-matching

> If an HTML file is found with a matching path to the current route requested, Pages will serve it. Pages will also redirect HTML pages to their extension-less counterparts: for instance, `/contact.html` will be redirected to `/contact`, and `/about/index.html` will be redirected to `/about/`.

先閱讀連結的 Cloudflare Pages 路由匹配文件。然後在 Gradle 外掛程式中找到現有的路徑解析入口，並為無副檔名的 HTML 路由、從 .html 路徑重新導向以及 index.html 目錄路由新增涵蓋。支援的路由能如描述般解析並重新導向即表示完成。

由索引模型根據 Issue 內容生成。