Examine source code of Trainator

{
  "manifest_version": 3,
  "name": "Trainator",
  "version": "0.1.0",
  "description": "Trainator data overlay for DB Navigator",
  "browser_specific_settings": {
    "gecko": {
      "id": "trainator@trainator.eu",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_popup": "popup/popup.html",
    "default_title": "Trainator",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.bahn.de/*"
      ],
      "js": [
        "content/content.js"
      ],
      "css": [
        "content/content.css"
      ],
      "run_at": "document_start"
    }
  ],
  "permissions": [
    "tabs",
    "scripting",
    "webNavigation"
  ],
  "host_permissions": [
    "*://*.bahn.de/*",
    "*://api.trainator.eu/*"
  ],
  "icons": {
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "web_accessible_resources": [
    {
      "resources": [
        "icons/icon16.png",
        "icons/icon48.png"
      ],
      "matches": [
        "*://*.bahn.de/*"
      ]
    }
  ]
}