版本：
文件：
- https://cdn.bootcdn.net/ajax/libs/leaflet-contextmenu/1.4.0/leaflet.contextmenu.css
- https://cdn.bootcdn.net/ajax/libs/leaflet-contextmenu/1.4.0/leaflet.contextmenu.js
- https://cdn.bootcdn.net/ajax/libs/leaflet-contextmenu/1.4.0/leaflet.contextmenu.min.css
- https://cdn.bootcdn.net/ajax/libs/leaflet-contextmenu/1.4.0/leaflet.contextmenu.min.js