Looks like there's a good one here: https://github.com/mvdan/sh/blob/master/cmd/shfmt/shfmt.1.scd PR's welcome. This should be pretty easy, you can follow the example of [`BlackStep`](https://github.com/diffplug/spotless/blob/main/lib/src/main/java/com/diffplug/spotless/python/BlackStep.java) and [`ClangFormatStep`](https://github.com/diffplug/spotless/blob/608e128381c89260f8a38fba985415c1f962ec7b/lib/src/main/java/com/diffplug/spotless/cpp/ClangFormatStep.java). See #672 for more details on how they work.
Looks like there's a good one here:
https://github.com/mvdan/sh/blob/master/cmd/shfmt/shfmt.1.scd
PR's welcome. This should be pretty easy, you can follow the example of
BlackStepandClangFormatStep. See #672 for more details on how they work.