Examine source code of Grok Highlight

{
  "manifest_version": 2,
  "name": "Grok Highlight",
  "version": "1.0",
  "description": "Highlights your messages in vibrant colors on grok.com for better visibility.",
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icons/icon48.png"
  },
  "background": {
    "scripts": [
      "lib/browser-polyfill.min.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.grok.com/*"
      ],
      "js": [
        "lib/browser-polyfill.min.js",
        "content.js"
      ]
    }
  ],
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4b7f6431-7e36-4813-b9ee-03138a8d6d8d}"
    }
  }
}