Strong Optimized Shelf Pin (IKEA)

This is a refinement of the original "yet another shelf pin" by oferfrid
The original pin is simple, elegant, and printed in the right direction for maximum strength.

### My Modifications:

1. Added a negative chamfer where the 'pin' meets the 'plate' - this ensures that the pin can come in full contact with the shelf. 3D printers just can't make precise right angles, there will always be a bit of a fillet, which makes it impossible to have the pin truly fully inserted into its hole.
2. Chamfered the bottom - this way there won't be any 'elephant foot' or bigger squished 1st layer even when using no raft.
3. Chamfered everything. Easier to insert into the hole, and also (insignificantly) stronger.
4. Now, there is also an OVERSIZED version of the pin. For extra security with wonky furniture.

### Usage

- Print a few of these at different scales. Depending on you printer's calibration and hole sizes, the ideal size differs.
- For my holes, the ideal scale was 91.5%,