Some keyboard shortcuts I’ve found for the portal:
ctrl+s saves your work
ctrl+/ removes and adds comments
ctrl+f finds words
ctrl+f ctrl+f or ctrl+h replaces words
ctrl+k to find words
ctrl+l to go to a line number
ctrl+p takes you to where the choice starts and ends
ctrl+{ and ctrl+} to move text right or left
ctrl+, to change how the portal looks
Some more obvious ones:
ctrl+z redo
ctrl+y redo the redo
ctrl+a highlights everything
ctrl+c to copy
ctrl+v to paste
ctrl+Arrow Keys to move around
ctrl+Backspace to delete words
ctrl± to zoom out
ctrl++ to zoom in
Have you guys found anymore? 
