Examine source code of base16

{
  "description": "base16 themes for the Firefox UI.",
  "manifest_version": 2,
  "name": "base16",
  "version": "1.3.1",
  "permissions": [
    "theme",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options.html"
  }
}