Examine source code of Netflix CC Remover

{
  "manifest_version": 2,
  "name": "Netflix CC remover",
  "version": "1.1resigned1",
  "description": "Removes closed captions from subtitles on Netflix.",
  "content_scripts": [
    {
      "matches": [
        "https://www.netflix.com/watch/*"
      ],
      "run_at": "document_idle",
      "css": [
        "index.css"
      ],
      "js": [
        "index.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{7332374e-f503-4b84-bcd6-bd336bd6a542}"
    }
  }
}