Examine source code of TWAddons

{
  "manifest_version": 2,
  "name": "VFB Bot",
  "version": "1.5",
  "description": "Its a bot.",
  "content_scripts": [
    {
      "matches": [
        "*://*.valkyriesfall.com/game*"
      ],
      "js": [
        "index.js"
      ]
    }
  ]
}