Short header declaring file distribution according to GNU Public Licence v3.0 for shell scripts
Inserts the declaration after the hashbag, if it exists, on .sh files. Copyright declaration follows the following schema.
# Copyright (C) YEAR Institute(s)
# SPDX-License-Identifier: GPL-3.0-only
# First commited by Author
EMPTY LINE
Edited by Eoin Clerkin