Examine source code of Speed Meter Overlay

{
  "manifest_version": 3,
  "name": "__MSG_extensionName__",
  "version": "1.0",
  "description": "__MSG_extensionDescription__",
  "permissions": [
    "scripting",
    "activeTab",
    "storage"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "icons": {
    "128": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e2a1644c-2f6e-5f38-a5f9-3374ae1cbf3f}",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "collects_data": false
      }
    }
  }
}