title: How to make sorting key insensitive in ag-grid?
body: <p>I am working in some grids and I notice that the sorting on all of them is key sensitive is there any way to change that. This is a part of my code.</p>
  
  <pre><code> columnDefs = [
  {
    headerName: 'Id', field: 'id', sort: 'asc', sortable: true, filter: true,
    checkboxSelection: true, resizable: true,
  },
  {
    headerName: 'Name', field: 'name', sortable: true, filter: true,
    checkboxSelection: false, editable: true, resizable: true,
  },
  {
    headerName: 'Description', field: 'description', sortable: true, filter: true,
    checkboxSelection: false, editable: true, resizable: true,
  },
    ];
  </code></pre>
  
  <p>Thank you for any possible given help.</p>
  
  <p>This is how i have implement the solution by ##wentjun##:</p>
  
  <pre><code>  constructor(private dialog: MatDialog, private adminService: AdminService) {}
  
    columnDefs = [
      {
        headerName: 'Id', field: 'id', sortable: true, filter: true,
        checkboxSelection: true, resizable: true,
      },
      {
        headerName: 'Name', field: 'name', sortable: true, filter: true,
        checkboxSelection: false, editable: true, resizable: true,
        comparator: this.customComparator,
      },
      {
        headerName: 'Description',  field: 'description', sortable: true, filter: true,
        checkboxSelection: false, editable: true, resizable: true,
      },
    ];
  
    customComparator(valueA, valueB) {
      return valueA.toLowerCase().localeCompare(valueB.toLowerCase());
    }
  </code></pre>