Examine source code of Web Dark Mode Ps

{
  "name": "Whatsapp Web Dark Mode",
  "version": "1.1",
  "description": "Enable dark mode on Whatsapp Web with a single click. Note: Any bugs encountered are due to Whatsapp, not the extension",
  "author": "luismzk",
  "homepage_url": "https://github.com/luismzk/whatsappweb-dark",
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "*://web.whatsapp.com/*"
      ],
      "js": [
        "wsScript.js"
      ],
      "run_at": "document_end"
    }
  ],
  "permissions": [
    "storage",
    "activeTab",
    "declarativeContent",
    "tabs"
  ],
  "browser_action": {
    "default_title": "WS Web Dark mode",
    "default_popup": "popup.html"
  },
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "{bcd0d7c1-85b3-44f0-bdd3-d416d2950952}"
    }
  }
}