in content.php change <?php the_excerpt(); ?> with
<?php the_content(); ?>
Or use this content.php file instead. I made changes in your content.php
<?php
/**
* The default template for displaying content
*
* Used for both single and index/archive/search.
*
* @package WordPress
* @subpackage AsperTheme
* @since AsperTheme 1.0
*/
?>
<!-- Create a div with a unique ID thanks to the_ID() and semantic classes with post_class()
the_ID(): Print the numeric ID of the current post
post_class(): Print out and add various post-related classes to the div tag
-->
<article id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
<header>
<h2 class="entry-title">
<a href="https://wordpress.stackexchange.com/questions/160512/<?php the_permalink(); ?>"
title="<?php printf(__('Permalink to %s', 'your-theme'), the_title_attribute('echo=0')); ?>"
rel="bookmark"><?php the_title(); ?>
</a>
</h2>
<div class="entry-meta">
<span class="meta-prep meta-prep-author"><?php _e('By ', 'your-theme'); ?></span>
<span class="author vcard">
<a class="url fn n" href="<?php echo get_author_link(false, $authordata -> ID, $authordata -> user_nicename); ?>"
title="<?php printf(__('View all posts by %s', 'your-theme'), $authordata -> display_name); ?>"><?php the_author(); ?>
</a>
</span>
<span class="meta-sep"> | </span>
<span class="meta-prep meta-prep-entry-date"><?php _e('Published ', 'your-theme'); ?></span>
<span class="entry-date">
<abbr class="published" title="<?php the_time('Y-m-d\TH:i:sO') ?>"><?php the_time(get_option('date_format')); ?></abbr>
</span>
<?php edit_post_link( __( 'Edit', 'your-theme' ), "<span class=\"meta-sep\">|</span>\n\t\t\t\t\t\t<span class=\"edit-link\">", "</span>\n\t\t\t\t\t" ) ?>
</div> <!-- .entry-meta -->
</header>
<div class="entry-content">
<?php the_content(__('Continue reading <span class="meta-nav">»</span>', 'your-theme')); ?>
<?php // the_excerpt(); ?>
<?php wp_link_pages('before=<div class="page-link">' . __( 'Pages:', 'your-theme' ) . '&after=</div>') ?>
</div> <!-- .entry-content -->
<div class="entry-utility">
<span class="cat-links">
<span class="entry-utility-prep entry-utility-prep-cat-links"><?php _e('Posted in ', 'your-theme'); ?></span>
<?php echo get_the_category_list(', '); ?>
</span>
<span class="meta-sep"> | </span>
<?php the_tags( '<span class="tag-links"><span class="entry-utility-prep entry-utility-prep-tag-links">' . __('Tagged ', 'your-theme' ) . '</span>', ", ", "</span>\n\t\t\t\t\t\t<span class=\"meta-sep\">|</span>\n" ) ?>
<span class="comments-link"><?php comments_popup_link( __( 'Leave a comment', 'your-theme' ), __( '1 Comment', 'your-theme' ), __( '% Comments', 'your-theme' ) ) ?></span>
<?php edit_post_link( __( 'Edit', 'your-theme' ), "<span class=\"meta-sep\">|</span>\n\t\t\t\t\t\t<span class=\"edit-link\">", "</span>\n\t\t\t\t\t\n" ) ?>
</div> <!-- #entry-utility -->
</article> <!-- #post-<?php the_ID(); ?> -->