Automatic srcset generation for responsive images (portrait, landscape and sizes)

[Tomasz-Kluczkowski]

Currently the way responsive images are used is to hardcode all their versions into the or tags. I would rather have a set of images with their resolutions and orientation encoded in the file names and generate a string representing srcset for or tags using Liquid's logic. All the static files like images are stored in jekyll's variable site.static_files. They include path, modified_time and extname as their attributes.