Collect errors from stdout also (i.e. not only from stderr)

[gamboz]

Thank you for the nice code :)

I have a request for a workaround (or enhancement): some formatters / linters output warnings and errors on stdout (instead of stderr) even when their exit code is non-zero.

For instance, djlint

echo "<p>hi" | djlint -  --lint  2>/dev/null
H025 1:0 Tag seems to be an orphan. <p>
Linted 1 file, found 1 error.

Would it be possible, in case of errors, to dump both stderr and stdout in the error buffer?