Add Webm medium quality preset and fix MP4/Webm presets - #385

Add Webm medium quality preset and fix MP4/Webm presets#385

benoit74 merged 2 commits into

openzim:mainopenzim/python-scraperlib:mainfrom

pawank925:issue-271-webm-medium-mp4-highpawank925/python-scraperlib:issue-271-webm-medium-mp4-highCopy head branch name to clipboard