Examine source code of Travellers' Helper

{
  "manifest_version": 3,
  "name": "__MSG_ext_name__",
  "version": "0.3.4",
  "description": "__MSG_ext_description__",
  "icons": {
    "16": "images/icon16.png",
    "48": "images/icon48.png",
    "128": "images/icon128.png"
  },
  "action": {
    "default_icon": "images/icon16.png",
    "default_popup": "popup.html"
  },
  "author": "Lei Wang",
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self'"
  },
  "short_name": "__MSG_ext_short_name__",
  "default_locale": "en",
  "browser_specific_settings": {
    "gecko": {
      "id": "travellers-helper@yolo.blue"
    }
  }
}