Examine source code of Free Scroll Button

{
  "name": "__MSG_extensionName__",
  "description": "__MSG_extensionDescription__",
  "manifest_version": 2,
  "version": "1.4.2",
  "homepage_url": "http://www.hjb-seite.de",
  "icons": {
    "16": "icons/16.png",
    "32": "icons/32.png",
    "48": "icons/48.png"
  },
  "applications": {
    "gecko": {
      "strict_min_version": "57.0"
    }
  },
  "permissions": [
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "js": [
        "hjbddorffsbcontentscript.js"
      ],
      "css": [
        "hjbddorffsb.css"
      ],
      "run_at": "document_idle",
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "default_locale": "en"
}