Vase cover (circles)

This creates a cover for a flower vase so that the flowers will be more upright.

This is my first scad project, so changes can occur.

This design can be changed using the following parameters:

- detail: the number of segments used to create the circles
- nofCircles: number of circle-elements for each ring
- height: height of the cover
- borderheigth: the extra height of the small border
- largeRadius: Radius of the vase, i.e. half of the diameter