Examine source code of GazoRepKiller

{
  "manifest_version": 2,
  "name": "GazoRepKiller",
  "version": "1.0.0",
  "description": "Remove Gazo reply from Tweet reply tree.",
  "content_scripts": [
    {
      "matches": [
        "*://twitter.com/*"
      ],
      "js": [
        "entrypoint.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "./*"
  ]
}