Ready-to-use template of module GenericForm. Include this template in module GenericForm using macro {layout '../path-to-latte-template'}.

Check {latte} source template to discover available hooks to customization or insert custom values:

{block #fieldControl}
    {if $input->name == 'demo_numeric_field'}
        {var $input->control->attrs['step'] = 1}
    {/if}

    {include parent}
{/block}