Examine source code of Dark Orange viever

{
  "manifest_version": 2,
  "name": "Dark orange viewer",
  "version": "2.0",
  "description": "dodaje pomarańczowo czarny motyw",
  "icons": {
    "48": "icons/border-48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "borderify.js"
      ]
    }
  ]
}