shfmt formats shell programs. It can use tabs or any number of spaces to
indent.

You can feed it standard input, any number of files or any number of
directories to recurse into. When recursing, it will operate on .sh and .bash
files and ignore files starting with a period. It will also operate on files
with no extension and a shell shebang.

If any EditorConfig files are found, they will be used to apply formatting
options.

WWW: https://github.com/mvdan/sh