Add missing final comments to top README.md files

In some cases the comments were there but there was no section heading.
In others the section was not there at all.

These files have NOT been checked in other ways. That will come another
day most likely and very possibly not until early next year.

1990/README.md

@@ -24,6 +24,13 @@ posted to comp.lang.c, comp.sources.unix, and alt.sources.  They have been made
 available on a wide number of USENET archive sites such as uunet.
 
 
+## Final Comments
+
+**IMPORTANT NOTE**: See [contact.html](/contact.html) for up to date contact details
+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) 1990,2023, Landon Curt Noll and Larry Bassel. All Rights Reserved.