Related posts thumbnail filter for Jekyll.
Jekyll Thumbnail Filter is a custom liquid filter for related posts thumbnails in the Jekyll static site generator.
Copy thumbnail_filter.rb into your Jekyll _plugins folder.
The filter will generate a link with the related post thumbnail as background image in the next order:
thumbnail_image in the Front Matter.thumbnail class in the CSS.Example:
Inside the site.related_post loop.
{{ post.content | thumbnail_url: post.url, post.title }}
See the examples content for full examples and output.