Examine source code of Automate PKP

{
  "manifest_version": 2,
  "name": "Automate PKP",
  "version": "1.0",
  "description": "Go throught PKP ticket buying",
  "icons": {
    "48": "icon/icon-48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.intercity.pl/pl/"
      ],
      "js": [
        "pkp.js"
      ]
    }
  ]
}