Examine source code of Nullify

{
  "manifest_version": 2,
  "name": "Nullify",
  "version": "3.0",
  "description": "This extension simplifies web pages by removing unnecessary clutter, reducing distractions, and providing a cleaner browsing experience. It also enhances accessibility by replacing images with their alt text.",
  "icons": {
    "128": "nullify_icon.png"
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "css": [
        "content.css"
      ],
      "js": [
        "alter.js"
      ],
      "run_at": "document_end"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{d265f395-84b8-460d-9101-a0cd7145d4e3}"
    }
  }
}