Examine source code of Successful

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#ffffff",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Successful",
  "manifest_version": 2,
  "description": "<a rel=\"nofollow\" href=\"https://outgoing.prod.mozaws.net/v1/b9d584e54a0a357ca9416e69f12e5db5f06b2ca6527045e27a30e4f86167b1b2/https%3A//www.youtube.com/watch%3Fv=fr7WY6iPySI\">https://www.youtube.com/watch?v=fr7WY6iPySI</a>"
}