More Customizable Shelf Hook

I loved the "Simple Customizable Shelf Hook" made by rocmtnguy, but wanted to be able to adjust the width of the hook independently of the wall thickness.

I'm also learning OpenSCAD, so I made this remix mostly by trial and error as I figured out what each part of the original code did. As part of that learning process I added comments, labelled the variables in the customizer, and reformatted some of the code for style.

I will upload photos of my test print soon. It is currently printing.

I sized the provided STL file for a hook to hang my indoor watering can from. I made the mistake of not saving the preset though, so these values may not be exactly the same!
hook_width: 25
wall_thick: 10
$fn: 75
shelf_thick: 16
depth: 60
arc: 60
nub type: spike
nub h: 12