Keep multiple lines on screen at the same time
When we writing codes for one page, the mouse focus is on the IDE, not zepline. But some lines would disappear while zipline lost the mouse focus, e.g. margin height/width lines.
Moreover, if zeplin can show all lines which I needed when developing this page, it could be very convenient since we don't need to keep checking the different lines and switching between ziplin and our IDE.
Maybe we could use "f" + right click to make this line to show/hide.