Attribute copyright to contributors as well (#62)

Co-authored-by: Eldred Habert <[email protected]>
Co-authored-by: Antonio Vivace <[email protected]>

Author: ISSOtm

LICENSE

@@ -1,4 +1,5 @@
-Copyright (c) 2021 Eldred Habert
+Copyright © 2021–2022 Eldred Habert
+Copyright © 2022–2023 gb-asm-tutorial contributors
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal