Examine source code of Merge All Windows

{
  "name": "Merge All Windows",
  "version": "0.2.0",
  "description": "Merge windows into the active one",
  "homepage_url": "https://github.com/austintraver/merge",
  "manifest_version": 2,
  "minimum_chrome_version": "80",
  "icons": {
    "128": "icon@128.png"
  },
  "permissions": [
    "tabs"
  ],
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+K",
        "mac": "MacCtrl+Shift+K"
      }
    }
  },
  "background": {
    "persistent": false,
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Merge All Windows",
    "default_icon": "icon@128.png"
  }
}