Add LICENSE

LICENSE

+Documentation
+-------------
+
+Copyright (C) 2018-2023 Provincia Autonoma di Bolzano
+
+This work is licensed under the Creative Commons Attribution-ShareAlike
+4.0 International License. To view a copy of this license, visit
+http://creativecommons.org/licenses/by-sa/4.0/ or send a letter to
+Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.
+
+Code snippets
+-------------
+Copyright (C) 2018-2023 Provincia Autonoma di Bolzano
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+