Examine source code of Klub Ruiny v2

{
  "theme": {
    "images": {
      "theme_frame": "ruiny.persona.header.jpg"
    },
    "colors": {
      "frame": "#a1a1a1",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Klub Ruiny v2",
  "manifest_version": 2,
  "description": "<a href=\"https://outgoing.prod.mozaws.net/v1/cb8fcc63e0e1216604739354eb921ed2808f01b02b5b195d9f6fba83ed6ee343/http%3A//klubruiny.sk\" rel=\"nofollow\">http://klubruiny.sk</a>"
}