Examine source code of ytsync-silph

{
  "manifest_version": 3,
  "name": "ytsync-silph",
  "version": "1.0",
  "permissions": [
    "tabs",
    "scripting",
    "webNavigation",
    "storage"
  ],
  "action": {
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.youtube.com/watch*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "host_permissions": [
    "https://www.youtube.com/*"
  ],
  "icons": {
    "128": "icon_128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "ytsync-silph@example.com"
    }
  }
}