Plugin to truncate and add an anchor "read more" in the posts of jekyll

post.html

<div class="">
  <div class="entry">
    <h2 class="title"><a href="{{ post.url }}">{{ post.title }}</a></h2>
    <div class="byline">Escrito el {{ post.date | date:"%d/%m/%Y" }}</div>

    <div class="body">
      {% if hide_extended %}
		{% if post.readmore %}
			{{ post.content | truncate }}
		    <a href="{{ post.url }}/#more" class="more-link"><span class="readmore">Read more»</span></a>
		{% else %}
      		{{ post.content }}
		{% endif %}
      {% endif %}
    </div>
    <div class='footer'>
    </div>
    <br />
    <br />
  </div>
</div>

read_me.rb

module Jekyll
  
  class Post
    alias_method :original_to_liquid, :to_liquid
    def to_liquid
      original_to_liquid.deep_merge({
        'readmore' => content.match('<!--more-->') ? content.split('<!--more-->').first : nil
      })
    end
  end
  
  module ReadMe
    
    def truncate content
      more_tag = '<!--more-->'
      if content.match more_tag
        content = content.match(more_tag) ? content.split('<!--more-->').first : nil
        content += '... '
      end
      content
    end
  end
end

Liquid::Template.register_filter(Jekyll::ReadMe)