nested demo fix, bug template

Author: adumesny

ISSUE_TEMPLATE.md

@@ -3,11 +3,12 @@ Describe your issue here.
 
 ## Your environment
 * version of gridstack.js AND if using HTML5 vs Jquery plugin (v3+) - DON'T SAY LATEST as that doesn't mean anything a month/year from now.
-* which browser and its version
+* which browser/OS
 
 ## Steps to reproduce
-MUST provide a working demo (keep it simple!) and steps, you can use this as a base:
-https://jsfiddle.net/adumesny/jqhkry7g
+You **MUST** provide a working demo (keep it simple!) and steps, you can use [this template](https://jsfiddle.net/adumesny/jqhkry7g) as a base.
+
+If un-sure if lib bug, or questions use [slack channel](https://gridstackjs.troolee.com/) instead!
 
 ## Expected behavior
 Tell us what should happen

demo/nested.html

@@ -54,14 +54,15 @@ <h1>Nested grids demo</h1>
     let grid = GridStack.addGrid(document.querySelector('.container-fluid'), json);
 
     addNewWidget = function(selector) {
+      let subGrid = document.querySelector(selector).gridstack;
       let node = {
-        x: Math.round(12 * Math.random()),
+        x: Math.round(6 * Math.random()),
         y: Math.round(5 * Math.random()),
-        w: Math.round(1 + 3 * Math.random()),
-        h: Math.round(1 + 3 * Math.random()),
+        w: Math.round(1 + 1 * Math.random()),
+        h: Math.round(1 + 1 * Math.random()),
         content: count++
       };
-      grid.addWidget(node);
+      subGrid.addWidget(node);
       return false;
     };
 

doc/CHANGES.md

@@ -5,6 +5,7 @@ Change log
 <!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
 **Table of Contents**  *generated with [DocToc](http://doctoc.herokuapp.com/)*
 
+- [4.0.3-dev](#403-dev)
 - [4.0.3 (2021-3-28)](#403-2021-3-28)
 - [4.0.2 (2021-3-27)](#402-2021-3-27)
 - [4.0.1 (2021-3-20)](#401-2021-3-20)
@@ -51,6 +52,8 @@ Change log
 - [v0.1.0 (2014-11-18)](#v010-2014-11-18)
 
 <!-- END doctoc generated TOC please keep comment here to allow auto update -->
+## 4.0.3-dev
+
 ## 4.0.3 (2021-3-28)
 
 - fix [#1693](https://github.com/gridstack/gridstack.js/issues/1693) `load` after `init()` broken in 4.x