Examine source code of Video Injector

{
  "description": "Injects a standard video container in place of proprietary containers.",
  "manifest_version": 2,
  "author": "tasadar2",
  "name": "Video Injector",
  "version": "1.0.5",
  "homepage_url": "https://github.com/tasadar2",
  "content_scripts": [
    {
      "matches": [
        "https://*/*"
      ],
      "js": [
        "video-injector.js"
      ],
      "run_at": "document_end"
    }
  ],
  "applications": {
    "gecko": {
      "id": "{768d1ceb-da12-4d33-8f9f-b4b70452ebe7}"
    }
  },
  "permissions": [
    "https://transpiria.com/*"
  ],
  "icons": {
    "64": "assets/icon.svg",
    "96": "assets/icon.svg",
    "128": "assets/icon.svg"
  }
}