Minimot Bit holder parameterized

I really liked the original but i found that the holes were too wide for my parts. (3 mm holes and the shaft being about 2.2 mm)
The block was 15 mm high and had a "free space" of 4 mm below the toolhole.
I have reduced it by 4 mm to save material.

As you can see in the picture, the original and my derivate can link together.
Respect to Arvin for this.

One enhancement that could be done is to put the linking pins and holes in the middle of the side. It is now slightly off-center.