Examine source code of Postmates Dark Mode

{
  "description": "Gives the Postmates Order Tracking page a dark mode",
  "manifest_version": 2,
  "name": "Postmates Dark Mode",
  "version": "2.0",
  "icons": {
    "16": "images/postmates16.png",
    "32": "images/postmates32.png",
    "48": "images/postmates48.png",
    "128": "images/postmates128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.postmates/order/*"
      ],
      "js": [
        "dark.js"
      ]
    }
  ]
}