Examine source code of Google Container Shortcut

{
  "manifest_version": 2,
  "name": "Google Container Shortcut",
  "version": "1.6",
  "description": "Open Google containers using a dedicated button or a keyboard shortcut.",
  "applications": {
    "gecko": {
      "id": "firefox.google.container.shortcut@ayusaxena.com"
    }
  },
  "icons": {
    "48": "assets/icon48.png",
    "96": "assets/icon96.png"
  },
  "options_ui": {
    "browser_style": true,
    "page": "options/options.html"
  },
  "permissions": [
    "tabs",
    "contextualIdentities",
    "contextMenus",
    "cookies",
    "storage",
    "webRequest",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "commands": {
    "open-google-container": {
      "suggested_key": {
        "default": "Alt+E",
        "mac": "Alt+E"
      },
      "description": "Open a tab in the Google container"
    }
  },
  "browser_action": {
    "browser_style": true,
    "default_icon": {
      "48": "assets/icon48.png",
      "96": "assets/icon96.png"
    }
  }
}