As of BBEdit 13.1, the HTML Tidy built-ins are back and you should use those instead. This gist is so old it refers to "OS X", c’mon!
If for some reason you are using this, note @ryanfrancesconi’s comment about the correct place to put the file when using sandboxed versions of BBEdit.
I'm extremely curious to know what the difference is. If it seriously is still useful I'll wrap it up in a
.bbpackage
to make installation simpler.