There needs to be a way to set custom image sizes, or this wiki is useless to me.
There's a proposal to add sizes to CommonMark spec here: https://github.com/jgm/CommonMark/wiki/Deployed-Extensions#image-size
Can't believe that's not in there already. There's a thread with some asshats dissing the idea over at https://talk.commonmark.org/t/support-for-image-dimensions/148/7
There's extensive support for images sizes on Wikipedia that you can see here:
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