## Subject of the issue
Describe your issue here.

## Your environment
* version of gridstack.js
* which browser and its version

## Steps to reproduce
Tell us how to reproduce this issue. Please provide a working demo, you can use [this template](https://jsfiddle.net/dweiss/dqyvh6vr/) as a base.

## Expected behaviour
Tell us what should happen

## Actual behaviour
Tell us what happens instead

Add issue template and base demo of gridstack.js.
Add issue template and base demo of gridstack.js.
