Picture with parameters name

[AlexDep]

Hello, Thank you for the work. It would be very useful to add in the documentation what represents each parameters on a picture of a threaded screw for example.

For example, fusion360 use different terminology and it's hard to see which one it is on the parameters of these openscad modules : https://productdesignonline.com/fusion-360-tutorials/3d-printed-threads-model-them-in-fusion-360/