fix markdown links to .png files that use a %%TOKEN%%

2018/algmyr/index.html

@@ -442,7 +442,7 @@ could listen to a cacophony of chirpy characters.</p>
 from hearing. But even without training you can easily read along with the
 printed characters and have the sound make sense with the look of the
 characters.</p>
-<p>See image <a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2018/algmyr/spoiler.png">spoiler.png</a> for an example spectrogram.</p>
+<p>See image <a href="spoiler.png">spoiler.png</a> for an example spectrogram.</p>
 <h3 id="limitations">Limitations</h3>
 <p>There is no error checking done when opening files, so expect segfaults if you
 provide the wrong path to a file.</p>