Examine source code of orf.at mark-read-articles

{
  "manifest_version": 2,
  "name": "Orfatshowonlynewarticles",
  "version": "1.0",
  "description": "Show only articles on orf.at main page, that are new and you havent seen them. All Articles that you have seen 15min before dont show up again",
  "icons": {
    "48": "icons/orfatshowonlynewarticles-48.png",
    "96": "icons/orfatshowonlynewarticles-96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.orf.at/*"
      ],
      "js": [
        "dontshowarticles.js"
      ],
      "css": [
        "dontshowarticles.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "orfatshowonlynewarticles@koehrer.at"
    }
  }
}