Grouped Header

To enable grouped header, it needs to add sub columns property in any column.

new FancyGrid({
  ...
  defaults: {
    type: 'number',
    width: 100
  },
  columns: [{
    title: 'Company',
    index: 'name',
    type: 'string',
    width: 200,
  }, {
    text: 'Stock Price',
    columns: [{
      title: 'Price',
      index: 'price'
    }, {
      title: 'Change',
      index: 'change'
    }, {
      title: '% Change',
      index: 'pctChange'
    }]
  }, {
    title: 'Last Updated',
    index: 'lastChange',
    type: 'string',
    width: 97
  }]
  ...