Better Folding Tablet Stand

This is a specific Remix of the referenced Things with even more enhancements that make it better for many tablets such as the iPad.
- Wider, with a usable range of angles
- Cutout added for lower screen access and to more easily grab the stylus.
- Added a front porch for a stylus (or one extra angle).
- Doesn't use "Arm Rests" because they are tricky to print.
- Add four small protrusions to hold the folded stand in place.