Fix: Attribute template's copyright to specified author name

If the user is putting their code on the `ImperialCollegeLondon` GitHub org they probably should be attributing the copyright to ICL, but I'm not sure it's worth the effort of adding another prompt for this. In any case, it certainly shouldn't be attributed to me, so let's fix that.

{{ cookiecutter.project_slug }}/LICENSE

@@ -1,6 +1,6 @@
 BSD 3-Clause License
 
-Copyright (c) 2024, Alex Dewar
+Copyright (c) 2024, {{ cookiecutter.author }}
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are met: