Examine source code of Play A Sound

{
  "manifest_version": 2,
  "name": "Play A Sound",
  "description": "This extension will play a sound so you can check if your audio works!",
  "version": "1.0",
  "browser_action": {
    "default_icon": "assets/icon.png",
    "default_popup": "popup.html"
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+A",
        "mac": "MacCtrl+Shift+A"
      },
      "description": "Opens popup.html"
    }
  }
}