fix intermittent bugs in how arrow keys work in epic description

When editing a capability description in Aha (such as https://niceactimize4.aha.io/epics/XPROG-E-503?active_tab=description&full_screen=7154518607894442779) (our capabilities might be your epics), using left and right arrow keys moves the cursor left and right, whereas using up and down arrow keys makes the page skip up and down (like fast scrolling). Undo, control z is not working as expected either. This problem is intermittent but super frustrating. I am using Chrome.