Examine source code of Kuro

{
  "manifest_version": 2,
  "name": "Kuro",
  "version": "1.0",
  "description": "Makes Certain Websites Dark Themed",
  "icons": {
    "48": "kuro.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.yourworldoftext.com/*"
      ],
      "js": [
        "yourworldoftext.js"
      ]
    }
  ]
}