Examine source code of stylesheet_injector

{
  "version": "1.0",
  "manifest_version": 2,
  "name": "stylesheet_injector",
  "content_scripts": [
    {
      "matches": [
        "https://*/*"
      ],
      "js": [
        "default.js",
        "content.js"
      ]
    }
  ],
  "options_ui": {
    "page": "options.html",
    "browser_style": false,
    "open_in_tab": false
  },
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f39c0574-f651-4f8f-9463-037bba61392a}"
    }
  }
}