Website: Bounty: Add links to writeups for unclaimed bounties

I've reached out to all of these authors asking if they would like to
claim the bounty and no one did. Let's list them on the website anyway
since it's fun to read about them. :^)

Meta/Websites/serenityos.org/bounty/index.html

@@ -37,5 +37,13 @@
     <p>
         To claim a reward, get in touch with me either on IRC (<b>kling</b> on Freenode) or via <b>kling@serenityos.org</b>
     </p>
+    <p><b>Unclaimed bounties:</b></p>
+    <ul>
+        <li><b>2020-12-22:</b> <b>ALLES! CTF</b> found a kernel LPE due to missing EFLAGS validation in <code>ptrace()</code>. (<a href="https://github.com/allesctf/writeups/blob/master/2020/hxpctf/wisdom2/writeup.md">Writeup and exploit</a>)</li>
+        <li><b>2020-12-20:</b> <b>yyyyyyy</b> found a kernel LPE due to a race condition between <code>execve()</code> and <code>ptrace()</code>. (<a href="https://hxp.io/blog/79/hxp-CTF-2020-wisdom2/">Writeup and exploit</a>)</li>
+        <li><b>2019-12-30:</b> <b>Fire30</b> found a kernel LPE due to bad userspace pointer validation. (<a href="https://github.com/Fire30/CTF-WRITEUPS/tree/master/36c3_ctf/wisdom">Writeup and exploit</a>)</li>
+        <li><b>2019-12-29:</b> <b>braindead</b> found a kernel LPE due to a TOCTOU bug in <code>clock_nanosleep()</code>. (<a href="https://github.com/braindead/ctf-writeups/tree/master/2019/36c3/wisdom">Writeup and exploit</a>)</li>
+
+    </ul>
 </body>
 </html>