Group input for pegboard caddy

[bwente]

Notes from the previous post.

@markevans36301

• Support spacing is always at one-inch increments,
• setting holes to zero will let you go freestyle with the cutouts,
• changing thickness doesn’t adjust the joint or the support half-lap
• needs an additional kerf adjustment for fine-tuning
• need to be able to adjust the distance between shelves
• need to be able to control the top and bottom shelf holes independently
• The readme page needs to explain what each variable does.

@markevans36301 Does this design need kerf?