A Jekyll/Liquid filter to calculate the read time of an article based on the formula used by Medium.
TL;DR: 275 WPM, add 12 seconds for first image, 11 for next, etc., down to a minimum of 3 seconds per image
Just drop read_time.rb into your _plugins folder. Simple as that!
{{ page.content | read_time }}
Note: this plugin requires img tags to be in the form of <img ... />. If you're using this on a post listing page, make sure to markdownify the post content first.