Reverse dependencies for extras

Latest version of the following gems require extras

Gem	Version	Date	Downloads
jekyll-assets +3.04 Million Downloads	`3.0.12` November 13, 2018	November 13, 2018	3.04 Million
liquid-tag-parser +597 Thousand Downloads	`2.0.2` March 27, 2020	March 27, 2020	597 Thousand
docker-template +57.6 Thousand Downloads	`0.22.0` November 03, 2018	November 03, 2018	57.6 Thousand