Examine source code of Auto Focus Search

{
  "manifest_version": 2,
  "name": "Auto Focus Search",
  "version": "1.0",
  "description": "Automatically focuses on the first search input box when a page loads.",
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "focus.js"
      ],
      "run_at": "document_end"
    }
  ],
  "icons": {
    "48": "icon.png",
    "128": "icon.png"
  },
  "applications": {
    "gecko": {
      "id": "autofocussearch@example.com",
      "strict_min_version": "60.0"
    }
  }
}