Examine source code of Document Downloader

{
  "manifest_version": 2,
  "name": "Document Downloader",
  "version": "1.0.0",
  "description": "Download embedded documents (PDF, DOC, DOCX, XLS, XLSX, PPT, PPTX) from any website",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [
    "activeTab",
    "downloads",
    "storage",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_action": {
    "default_icon": {
      "48": "icons/icon-48.png"
    },
    "default_title": "Document Downloader",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "document-downloader@example.com",
      "strict_min_version": "58.0",
      "data_collection_permissions": {
        "required": [
          "websiteContent"
        ],
        "optional": []
      }
    }
  },
  "author": "Document Downloader Extension"
}