Examine source code of Twitter to Nightlight

{
  "manifest_version": 2,
  "name": "Twitter to Nightlight",
  "version": "1.2",
  "description": "Adds a button to Twitter which lets you repost tweets directly to Nightlight with proper attribution.",
  "homepage_url": "https://github.com/iTenerai/twitter-to-nightlight",
  "icons": {
    "38": "assets/38.png",
    "128": "assets/128.png"
  },
  "permissions": [
    "cookies",
    "activeTab",
    "tabs",
    "notifications",
    "https://twitter.com/*",
    "https://x.com/*",
    "https://night-light.cz/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "https://twitter.com/*",
        "https://x.com/*",
        "https://night-light.cz/*"
      ],
      "js": [
        "content-script.js"
      ],
      "css": [
        "styles.css"
      ]
    }
  ],
  "web_accessible_resources": [
    "assets/logo_monochrome.png"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{e630e55d-3b90-405a-9610-9c346ef60808}"
    }
  }
}