OK, @dhj said that I can reveal this easter egg (there are more 
).
So, @jonathanthomas83 here is the missing piece:
(1) Shift + click the linear shape:
(2) A dialog box will open, prompting you to enter the number of steps (e.g. 8)
(3) And you’ve got yourself a nice shaped curve:
~
You can also set Min and Max and repeat the procedure, or vice versa (create steps and then set Min and Max).
