Examine source code of onlymaths.gr unlock

{
  "manifest_version": 2,
  "name": "onlymaths.gr unlock",
  "version": "0.3",
  "description": "Removes ad link from the pdf files ( when its bold its ad-free )",
  "content_scripts": [
    {
      "matches": [
        "*://*.onlymaths.gr/*"
      ],
      "js": [
        "onlymaths.js"
      ]
    }
  ],
  "permissions": [
    "<all_urls>"
  ]
}