Fix the spelling of "closeable" in the documentation.
Fix the spelling of "closeable" in the documentation.

Youraiseme/webui-popover,sandywalker/webui-popover,Youraiseme/webui-popover,addmitriev/webui-popover,wisdomcsharp/webui-popover,addmitriev/webui-popover,wisdomcsharp/webui-popover,sandywalker/webui-popover,niftytushar/webui-popover,niftytushar/webui-popover