I based this on STL to OpenSCAD Converter from https://www.thingiverse.com/thing:1383325 but it had a lot of issues, so I added file verification, styling, fixed typos, updated dependencies, included all the references properly, optimized code, and removed deprecated references.

Thingiverse use case:

In OpenSCAD you can use import(example.stl) to import an STL. However, Thingiverse Customizer doesn't support the import command, and it requires that everything resides in one .scad file. With this tool, you can convert all your STLs to OpenSCAD modules, copy and paste each module into one big SCAD file, and call the module instead of using import().