Examine source code of Upload file from URL

{
  "description": "Upload files directly from a URL, without needing to have them on your computer!",
  "version": "1.2.1",
  "name": "Upload file from URL",
  "permissions": [
    "<all_urls>"
  ],
  "background": {
    "page": "background.html"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "public/icon.png"
  },
  "icons": {
    "128": "public/icon.png"
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+U"
      }
    }
  },
  "web_accessible_resources": [
    "public/**/*.png",
    "public/**/*.jpg",
    "public/*.woff2"
  ],
  "manifest_version": 2
}