improve Copyright and CC

The inc/footer.default.html now has a common Copyright and CC BY-SA
4.0 License section for all generated HTML files.

All markdown files have a similar Copyright and CC
at the bottom in the form of an HTML comment.

2012/README.md

@@ -108,10 +108,16 @@ as well as details on how to provide fixes to any of the entries.
 See also [the IOCCC FAQ](../faq.html) for addition information on the IOCCC.
 
 
-# Copyright and License
+<!--
 
-Copyright (c) 2012,2023, Landon Curt Noll and Leonid A. Broukhis. All Rights Reserved.
-This work is licensed under a [Creative Commons CC BY-SA 4.0 DEED Attribution-ShareAlike
-4.0 International](https://creativecommons.org/licenses/by-sa/4.0/) license.
-If you do use this work in some form, the [IOCCC judges](../judges.html) would appreciate
-(but does not require) if you were to [send us a note about your use](../contact.html).
+    Copyright © 1984-2024 by Landon Curt Noll. All Rights Reserved.
+
+    You are free to share and adapt this file under the terms of this license:
+
+	Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)
+
+    For more information, see:
+
+	https://creativecommons.org/licenses/by-sa/4.0/
+
+-->