try this instead it will add the link to the Author Title:
<div class="author-box">
<?php global $post; ?>
<div class="avatar"><?php echo get_avatar( get_the_author_meta( 'ID' )); ?></div>
<h5 class="author-title"><a href="<?php echo get_author_posts_url( get_the_author_meta( 'ID' ) ); ?>" title="Read more"><?php printf( esc_attr__( 'About %s', 'the author' ), get_the_author_meta( 'display_name') );?></a></h5>
<div class="author-summary">
<p class="author-description"><?php echo wp_kses( get_the_author_meta( 'description' ), null ); ?></p>
</div>
</div>