Update copyright date in readme

readme.md

@@ -42,7 +42,7 @@ https://facelessuser.github.io/BracketHighlighter/
 
 Released under the MIT license.
 
-Copyright (c) 2013 - 2021 Isaac Muse <isaacmuse@gmail.com>
+Copyright (c) 2013 - 2022 Isaac Muse <isaacmuse@gmail.com>
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
 documentation files (the "Software"), to deal in the Software without restriction, including without limitation the