FAQs - kward/shflags GitHub Wiki
How can I add newlines into the string of FLAGS_HELP (the custom usage description) variable? You can do so with a here document. E.g.,
FLAGS_HELP=$(cat <<EOF
USAGE: $0 [flags] command
commands:
backup: snapshot, and then take backups of the snapshots
snapshot: take snapshots of all the filesystems
EOF
)