Examine source code of Tab Randomizer

{
  "manifest_version": 2,
  "name": "TabRandomizer",
  "version": "1.3",
  "description": "Randomize (shuffle) all tabs in the current window",
  "icons": {
    "48": "icons/randomizer-48.png"
  },
  "permissions": [
    "<all_urls>",
    "tabs",
    "tabGroups",
    "storage"
  ],
  "browser_action": {
    "default_icon": "icons/randomizer-48.png",
    "default_title": "Tab Randomizer",
    "browser_style": true,
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "commands": {
    "randomize-tabs": {
      "suggested_key": {
        "default": "Alt+Shift+R"
      },
      "description": "Randomize all the tabs in the current window."
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b2b48dec-3245-4ac1-a107-a6c3ef203859}"
    }
  }
}