Retract-a-gate post bracket

A bracket designed to mate the [Retract-a-gate](https://retract-a-gate.com/) post to my house's rectangular railing. Features a recessed track for a ~5mm zip-tie. I tried to make the OpenSCAD file parametric-ish, so this can probably be customized to other rectangular railings without too much trouble.

Please feel free to use and adapt this design but note that I cannot take responsibility for the part's performance or the safety of anything or anyone it's used to secure. Use at your own risk!