Please add support for start and end of the item set in the GridRenderer, so that the HtmlTableGridRenderer can render the <tbody> tag.

I was able to implement this by modifying the GridRenderer.RenderItems() method like so:

protected virtual void RenderItems()
{

RenderBodyStart();

bool isAlternate = false;
foreach(var item in DataSource)
{
    RenderItem(new GridRowViewData<T>(item, isAlternate));
    isAlternate = !isAlternate;
}

RenderBodyEnd();

}

And making the following additions:

To GridRenderer:

    protected abstract void RenderBodyStart();
    protected abstract void RenderBodyEnd();

To HtmlTableGridRenderer:

    protected override void RenderBodyStart()
    {
        RenderText("<tbody>");
    }

    protected override void RenderBodyEnd()
    {
        RenderText("</tbody>");
    }