Examine source code of Old Reddit Destyler

{
  "manifest_version": 3,
  "name": "Old Reddit Destyler",
  "version": "1.0.0",
  "description": "Removes custom styles from Old Reddit subreddits.",
  "host_permissions": [
    "https://old.reddit.com/"
  ],
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://old.reddit.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_start"
    }
  ],
  "icons": {
    "16": "icon/16.png",
    "48": "icon/48.png",
    "128": "icon/128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "old-reddit-destyler@chriswales.uk"
    }
  }
}