title: ag-grid export select rows by default
body: <p>I'm using ag-grid (angular) and I would like to export the select rows to CSV or Excel. From what i researched on documentation this feature seems to be possible only using an external button (yellow on image) and not from the export inside of the table (red underline in image).</p>
  
  <p>Is this possible to export selected line through the table itself (red underline in image)?</p>
  
  <p>I'm imagining a multi selection feature in table and if I've no elements selected so the ag-grid export all data and if i've some elements selected then the ag-grid only export the selected one.</p>
  
  <p><a href="https://i.stack.imgur.com/0kdh3.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/0kdh3.png" alt="enter image description here"></a></p>