Examine source code of DOM Update Highlighter

{
  "name": "DOM Update Highlighter",
  "description": "Highlight DOM elements that are being updated",
  "version": "1.0.3",
  "permissions": [
    "activeTab",
    "scripting"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "type": "module"
  },
  "manifest_version": 3,
  "icons": {
    "32": "icon32.png",
    "64": "icon64.png",
    "128": "icon128.png"
  },
  "action": {
    "default_title": "Highlight DOM changes on this webpage as they happen"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "dom-update-highlighter@klntsky.dev",
      "strict_min_version": "42.0"
    }
  }
}