Buildkite inline video annotations from link URL

inline_buildkite_video_links.user.js

// ==UserScript==
// @name         Inline Video Links in Buildkite
// @description  Buildkite (really the markdown parser under the hood) doesn't support video annotations, so this will 
// @namespace    https://sgregson.dev
// @version      1.0
// @author       sgregson
// @match        https://buildkite.com/*
// ==/UserScript==

(() => {
  // Find all links pointing to mp4 files
  const videoLinks = document.querySelectorAll('a[href$=".mp4"]')

 videoLinks.forEach(e => {
   const video = document.createElement("video")
   const source = document.createElement("source")
   
   source.setAttribute("type", "video/mp4");
   source.setAttribute("src", e.href);
   video.setAttribute("width", "100%");
   video.setAttribute("controls", "true");
   video.appendChild(source)
   
   // Inline the video after the link
   e.parentNode.append(video);
 })
})()

this can be improved, should implement a mutation observer for items which are revealed after the document loads