Examine source code of Clean Chat for Twitch

{
  "name": "Clean Chat for Twitch",
  "version": "1.6",
  "manifest_version": 2,
  "description": "Reduces twitch chat clutter, and enlarges emote-only message emotes.",
  "content_scripts": [
    {
      "matches": [
        "https://twitch.tv/*",
        "https://www.twitch.tv/*"
      ],
      "css": [
        "style.css"
      ],
      "js": [
        "script.js"
      ],
      "world": "MAIN"
    }
  ],
  "icons": {
    "16": "icon16.png",
    "32": "icon32.png",
    "48": "icon48.png",
    "96": "icon96.png",
    "128": "icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a718a7fe-4393-4835-b654-17f787b0806c}"
    }
  }
}