Examine source code of cute cat

{
  "theme": {
    "images": {
      "theme_frame": "firefoxcatdesign.jpg"
    },
    "colors": {
      "frame": "#000000",
      "tab_background_text": "#212121"
    }
  },
  "version": "2.0",
  "name": "cute cat",
  "manifest_version": 2,
  "description": "i have not done much at all to this image. all credit given to \n\n<a rel=\"nofollow\" href=\"https://outgoing.prod.mozaws.net/v1/75ffaaaacba2f71d57bc13523bd63a5ebcadb766f4c817d0612ffd0226597986/http%3A//pc-stock.deviantart.com/art/Cat-Stock-001-92863475%23commentbody\">http://pc-stock.deviantart.com/art/Cat-Stock-001-92863475#commentbody</a>"
}