contrib/subtree: Fix typo (s/incldued/included/)

Signed-off-by: Paul Campbell <pcampbell@kemitix.net>
contrib/subtree: Replace invisible carriage return with a visible \r

The ctrl-M (^M) character used for the carriage return (CR) is not visible
in all (most) text editors and is often silently converted to a new
line (NL) or CR/NL combo.

'say' is a wrapper for echo with accepts the option -e to interperet
escaped characters. \r becomes a CR, yet is not munged by text
editors.

Signed-off-by: Paul Campbell <pcampbell@kemitix.net>