Make LICENSE readable by GitHub

Author: Ives van Hoorne

LICENSE

@@ -1,5 +1,15 @@
-Copyright (c) Ives van Hoorne
+CodeSandbox. An online code editor tailored for web application development.
+Copyright (C) 2017  Ives van Hoorne
 
-Up is an Open Source project licensed under the terms of
-the GPLv3 license. Please see <http://www.gnu.org/licenses/gpl-3.0.html>
-for license text.
+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 <https://www.gnu.org/licenses/>.