Obsolete link / zip archive in README.md

[forrcaho]

README.md has this:

After you have openSCAD installed, you need to download the code and run it. running `git clone https://github.com/rsheldiii/openSCAD-projects.git` if you have git, or downloading [this zip](https://github.com/rsheldiii/openSCAD-projects/archive/master.zip) and extracting the directory should do it.

Which points to your openSCAD-projects repo instead of this one.

I would have submitted a PR, but there's also a reference to a zip file, and I didn't see a corresponding one for this project.