Examine source code of Fix Udemy

{
  "manifest_version": 2,
  "name": "Fix Udemy",
  "version": "1.0",
  "description": "Fixes Udemy video playback speed not saving between videos, this extension will store your speed preferences for each instructor and properly reload with that speed on all videos",
  "icons": {
    "48": "icons/udemyext-icon-96.png",
    "96": "icons/udemyext-icon-48.png"
  },
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.udemy.com/course/*/learn/lecture/*"
      ],
      "js": [
        "udemy.js"
      ]
    }
  ],
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{1009f301-2910-43b8-9049-1127ec636104}"
    }
  }
}