title: How to create ExtJS editable grid column indication using fontawesome 'fa fa-edit'
body: <p>I started learning ExtJS recently.I created a grid with columns(names,email , phone) and added some dummy data using store. Here column -("names") is editable column. when user sees that grid , he should come to know that (names) column is editable. For this I needed to add edit symbol( iconCls: 'fa fa-edit' fontawesome) to the right side of data in each column under "names" header,so that user can come to know that that column is editable.How can I achieve this.Please help me with this,I tried a lot but did not found a solution.Thanks in advance.</p>
  
  <p><strong>ExtJS grid code</strong>:</p>
  
  <p>Ext.define('FirstApp.view.main.List', {
      extend: 'Ext.grid.Panel',
      xtype: 'mainlist',
      columnLines: true,</p>
  
  <pre><code>requires: [
      'FirstApp.store.Personnel',
      'Ext.grid.filters.Filters'
  ],
  
  title: 'Personnel',
  collapsible: true,
  iconCls: 'icon-grid',
  frame: true,
  width: 700,
  height: 500,
  resizable: true,
  plugins: 'gridfilters',
  emptyText: 'No Matching Records',
  loadMask: true,
  stateful: true,
  stateId: 'stateful-filter-grid',
  
  store: {
      type: 'personnel',
      autoLoad: true,
      autoDestroy: true
  },
  tbar: [{
      text: 'Show Filters...',
      tooltip: 'Show filter data for the store',
      handler: 'onShowFilters'
  }, {
      text: 'Clear Filters',
      tooltip: 'Clear all filters',
      handler: 'onClearFilters'
  }],
  
  columns: [
      { text: 'Name',  dataIndex: 'name',flex:1,
          align: 'center',
          editor: {
              xtype: 'textfield',
              allowBlank: false
          },
          filter: {
  type: 'string',
      itemDefaults: {
      emptyText: 'Search for...'
  } }},
      { text: 'Email', dataIndex: 'email', flex: 1,filter: {
          type: 'string',
          itemDefaults: {
              emptyText: 'Search for...'
          } }},
      { text: 'Phone', dataIndex: 'phone', flex: 1 }
  ],
  selType: 'cellmodel',
  plugins: [
      Ext.create('Ext.grid.plugin.CellEditing', {
          clicksToEdit: 1
      })
  ]
  </code></pre>
  
  <p>});</p>
  
  <p><a href="https://i.stack.imgur.com/DtEwb.png" rel="nofollow noreferrer">refer Grid image with arrowd indication where that editable fontawesome should appear</a></p>