[list] show short description for scripts

[toshi0383]

If I have a script below,

#/bin/bash
#
# - description:
#       This is an awesome script.
#       It's really useful.
#

echo 😎

then cmdshelf list --description will parse them and display along side the default information.

~ $ cmdshelf ls --description
toshi0383:utils/awesome.sh - "This is an awesome script."
toshi0383:xcode/check-build-time.sh
toshi0383:xcode/open-device-support-dir.sh
toshi0383:xcode/check-expiring-mobileprovision.sh