Adding a third menu

gistfile1.txt

add_action( 'generate_before_footer','generate_tertiary_navigation_position' );
function generate_tertiary_navigation_position()
{
	?>
	<nav itemtype="http://schema.org/SiteNavigationElement" itemscope="itemscope" id="tertiary-navigation" role="navigation" class="tertiary-navigation">
		<div class="inside-navigation grid-container grid-parent">
			<?php do_action( 'generate_inside_navigation' ); ?>
			<button class="menu-toggle tertiary-menu-toggle" aria-controls="primary-menu" aria-expanded="false">
				<?php do_action( 'generate_inside_mobile_menu' ); ?>
				<span class="mobile-menu"><?php echo apply_filters('generate_mobile_menu_label', __( 'Menu', 'generate' ) ); ?></span>
			</button>
			<?php 
			wp_nav_menu( 
				array( 
					'theme_location' => 'primary',
					'container' => 'div',
					'container_class' => 'main-nav',
					'menu_class' => '',
					'fallback_cb' => 'generate_menu_fallback',
					'items_wrap' => '<ul id="%1$s" class="%2$s ' . join( ' ', generate_get_menu_class() ) . '">%3$s</ul>'
				) 
			);
			?>
		</div><!-- .inside-navigation -->
	</nav><!-- #site-navigation -->
	<?php
}
endif;