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.

2013/dlowe/index.html

@@ -413,7 +413,7 @@ with one argument or when all arguments are equal?</p>
 <p>and with Apple clang version 15.0.0 (clang-1500.0.40.1) in 2023, we get:</p>
 <pre><code>    1840985120 -2033041452 35979112</code></pre>
 <p>Which one is correct? :)</p>
-<p>NOTE: <code>make all</code> will compile <a href="fun.c">fun.c</a> but to provide a different compiler
+<p>NOTE: <code>make all</code> will compile <a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2013/dlowe/fun.c">fun.c</a> but to provide a different compiler
 you can do something like:</p>
 <pre><code>    make CC=clang fun</code></pre>
 <h2 id="authors-remarks">Author’s remarks:</h2>
@@ -426,9 +426,9 @@ you can do something like:</p>
 
     $ echo &quot;sparkline of file lengths: $(wc -c * | awk &#39;{print $1}&#39; | xargs ./sparkl)&quot;
     sparkline of file sizes: ▁▁▁▃▃▂▁▂▁▁▉</code></pre>
-<p>NOTE: this has been provided in <a href="slflen.sh">slflen.sh</a> so you can try:</p>
+<p>NOTE: this has been provided in <a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2013/dlowe/slflen.sh">slflen.sh</a> so you can try:</p>
 <pre><code>    ./slflen.sh</code></pre>
-<p>instead (which <a href="try.sh">try.sh</a> also uses).</p>
+<p>instead (which <a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2013/dlowe/try.sh">try.sh</a> also uses).</p>
 <h3 id="description">Description</h3>
 <p>This is a handy little tool for visualizing numeric series from the
 command line, using sparklines. Pass it a numeric series as arguments, and