Add better ksh support

[andrewimeson]

Ksh was not being detected properly for me by ALE

A file with this code would be run by ALE through /bin/sh -n and by shellcheck with -s sh, leading to it incorrectly complaining about process substitution being undefined in POSIX sh.

#!/bin/ksh

diff -w <(find expected_logs/ -maxdepth 1 | sed 's/.expected//' | sort) <(find logs/ -maxdepth 1 | sed -E 's/\.[^.]+\.log$//' | sort)

I tested it locally and it fixes my issue.

[w0rp]

Cheers! 🍻