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.

2019/diels-grabsch1/index.html

@@ -389,7 +389,7 @@ to qualify for the Best Short Program award! That said, can you compress it down
 to a one-liner, still producing files in the UNIX compress format, albeit
 sacrificing the compression ratio?</p>
 <p>Can you explain why the <code>/dev/zero</code> file compresses identically by the entry and
-the standard <code>compress(1)</code> tool (see <a href="try.sh">try.sh</a>), but the text file
+the standard <code>compress(1)</code> tool (see <a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2019/diels-grabsch1/try.sh">try.sh</a>), but the text file
 compresses differently? The judges know. :)</p>
 <h2 id="authors-remarks">Author’s remarks:</h2>
 <h3 id="a-tiny-compress-tool">A tiny “compress” tool:</h3>
@@ -400,7 +400,7 @@ compresses differently? The judges know. :)</p>
 <h4 id="check-for-correctness">Check for correctness:</h4>
 <pre><code>    zcat guidelines.txt.Z &gt; guidelines2.txt
     diff -s guidelines.txt guidelines2.txt</code></pre>
-<p>Of course you can also use <a href="../../2015/mills2/mills2.c">2015/mills2</a> instead of
+<p>Of course you can also use <a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2015/mills2/mills2.c">2015/mills2</a> instead of
 <code>zcat</code> to verify the output file. The achieved compression ratio roughly matches
 that of the classic Unix <code>compress(1)</code> tool. And the source code is very
 compressed, too: It has exactly the same size as the paragraph you are reading