Examine source code of The Developer Theme

{
  "manifest_version": 3,
  "name": "The developer theme",
  "version": "1.0",
  "description": "A theme focused on developers",
  "chrome_url_overrides": {
    "newtab": "newtab.html"
  },
  "permissions": [
    "storage",
    "activeTab"
  ],
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "developer-theme@narayan",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}