Grabs the maximum resolution for the images in the set
script only works on the images in an actual post (ex:https://knaiifu.tumblr.com/post/189790583347/roses), a limitation of tumblr's recent backend changes, but in exchange we get upgraded from 1280 to 2048 resolution
note: this script triggers pop-up blockers when opening multiple images at once so it works better if you allow tumblr to show pop-ups
EDIT: as of recent changes on tumblr's backend this script no longer works, i recommend this script instead that is capable of dealing with the update and gives full resolution tumblr images now https://greasyfork.org/en/scripts/36662-image-max-url
