Add to Internet history about UUCP

In the years 1991, 1992, 1993, 1994 and 1995 the README.md/index.html
files referred to the UUCP for mail with the text:

    For those who appreciate a bit of Internet history, this is how
    people used to contact the IOCCC in this given year

and I added to it the text:

    via Unix to Unix CoPy (UUCP)

where 'Unix to Unix CoPy (UUCP)' is a link to 'complete' the history.

1994/index.html

@@ -469,7 +469,8 @@ Also include anything else that you would like to see in future contests.
 See <a href="../contact.html">How to contact the IOCCC</a> for how to provide
 us with your comments and suggestions today.</p>
 <p>For those who appreciate a bit of Internet history, this is how
-people used to contact the IOCCC in this given year:</p>
+people used to contact the IOCCC in this given year, via <a href="https://en.wikipedia.org/wiki/UUCP#Mail_routing">Unix to Unix CoPy
+(UUCP)</a>:</p>
 <blockquote>
 <p>…!{sun,pacbell,uunet,pyramid}!hoptoad!judges<br>
 judges@toad.com</p>