Examine source code of WebP → JPEG Downloader

{
  "manifest_version": 2,
  "name": "WebP → JPEG Downloader",
  "version": "2.1.0",
  "description": "Silently converts WebP image downloads to JPEG. Right-click/long-press any image and Save as JPEG. Works on desktop and Android.",
  "browser_specific_settings": {
    "gecko": {
      "id": "{63de6c25-9fe6-4934-aa83-a254930ef466}",
      "strict_min_version": "58.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "permissions": [
    "downloads",
    "contextMenus",
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "icons": {
    "48": "icons/icon48.png",
    "96": "icons/icon96.png"
  }
}