custom-wp_query-pagination.php

<?php

// Yoink https://wordpress.stackexchange.com/a/154364
if ( ! function_exists( 'pagination' ) ) {
  function pagination( $paged = '', $max_page = '' ) {
      $big = 999999999; // need an unlikely integer
      if( ! $paged ) {
          $paged = get_query_var('paged');
      }

      if( ! $max_page ) {
          global $wp_query;
          $max_page = isset( $wp_query->max_num_pages ) ? $wp_query->max_num_pages : 1;
      }

      echo paginate_links( array(
          'base'       => str_replace( $big, '%#%', esc_url( get_pagenum_link( $big ) ) ),
          'format'     => '?paged=%#%',
          'current'    => max( 1, $paged ),
          'total'      => $max_page,
          'mid_size'   => 1,
          'prev_text'  => __( '«' ),
          'next_text'  => __( '»' ),
          'type'       => 'list'
      ) );
  }
}