(docs): forgot to add demo code for chkbox
(docs): forgot to add demo code for chkbox

swimlane/ngx-ui,Hypercubed/ngx-ui,swimlane/ngx-ui,Hypercubed/ngx-ui,swimlane/ngx-ui,Hypercubed/ngx-ui,Hypercubed/ngx-ui,swimlane/ngx-ui