fix many internal links

Fixed a number of internal links that need to
go to the GitHub site.

Ran `make www` to perform the above.

2000/index.html

@@ -394,7 +394,7 @@ that was not supplied with the entry.</li>
 them for the next IOCCC.</p>
 <p>We believe you will be impressed with this year’s winning entries. The <a href="jarijyrki/index.html">Best of
 Show</a> is a fine example of compact obfuscation. But don’t
-ignore the shorter entries. The <a href="natori/index.html">Best Small Program</a>, <a href="briddlebane/README.m">Best
+ignore the shorter entries. The <a href="natori/index.html">Best Small Program</a>, <a href="briddlebane/index.html">Best
 Abuse of User</a> and <a href="tomx/index.html">Most Complete Program</a>
 are well worth studying in detail.</p>
 <p>The <a href="dlowe/index.html">Worst Abuse of the Rules</a> is technically allowed by the