Multiboard - Multigrid - Baseplate to bracket screw (Remix of 13 mm Small Thread, Flat Head, Bolt)

Didn't find anything to lock down the baseplate to the brackets and still allowing the bins to fit, so remixed this.

Remix of: https://thangs.com/designer/Keep%20Making/3d-model/13%20mm%20Small%20Thread%2C%20Flat%20Head%2C%20Bolt-974055

Thanks for an awesome system Keep Making!