BST: 1/4 and 1/5 default snap areas / keyboard shortcuts (useful for SUW displays)

Howdy, long time BST user here.

With "Super UltraWide" displays becoming more and more common (e.g. Dell, LG and Samsung 49"), it'd be great to get default keyboard shortcuts for snapping windows to "quarters" and "fifths" of the screen, similar to the existing [left|middle|right] "third" options.