return-edit.js

return (
  <Fragment>
    <InspectorControls>
      <PanelBody title={ __( 'RSS Feed Settings' ) }>
        <RangeControl
          label={ __( 'Number of posts to be shown on the front-end' ) }
          value={ numberOfPosts }
          min='1'
          max='50'
          onChange={ onChangeNumber }
        />
        <ToggleControl
          label={ __('Display post description') }
          checked={ showDescription }
          onChange={ onChangeShowDescription }
        />
        <ToggleControl
          label={ __('Display post date') }
          checked={ showDate}
          onChange={ onChangeShowDate }
        />													
      </PanelBody>
    </InspectorControls>
  </Fragment>
);