Examine source code of Search Shortcut

{
  "manifest_version": 2,
  "name": "Search Shortcut",
  "version": "1.2",
  "developer": {
    "name": "Mert Bora ALPER",
    "url": "http://labs.boramalper.org"
  },
  "description": "Adds a shortcut (by default Ctrl+Y) to focus on the search box in webpages.",
  "icons": {
    "64": "icon64.png"
  },
  "background": {
    "scripts": [
      "browser-polyfill.min.js",
      "background.js"
    ]
  },
  "permissions": [
    "activeTab"
  ],
  "commands": {
    "focus": {
      "suggested_key": {
        "default": "Ctrl+Y",
        "mac": "MacCtrl+Y"
      },
      "description": "Focus on the search box."
    }
  }
}