Processing 4.2 pdez files!!

Wow! Processing 4.2 adds the new pde:// protocol which allows you to open Processing sketches in the PDE directly from the browser!! We should implement this into the site for all video pages!!

See: https://github.com/processing/processing4/releases/tag/processing-1292-4.2

cc @benfry @SableRaf

Will tackle this here first, but then I can add this to the Nature of Code website as well!

該 issue 未指定任何檔案或測試。請結合連結的 Processing 4.2 發行說明檢視網站的影片頁面，然後驗證所有影片頁面都支援透過 pde:// 協定開啟 Processing 草圖。

由索引模型根據 Issue 內容生成。