static: replace artwork

Artwork is from http://www.rd-sounds.com/C83.html

templates/footer.html

@@ -1,5 +1,5 @@
 <footer>
-    <a href="/"><img src="[[path|/mask-icon.svg]]" width="512" height="512" alt=""/>GrapheneOS</a>
+    <a href="/"><img src="[[path|/mask-icon.svg]]" width="512" height="512" alt=""/>Hakurei</a>
     <ul id="social">
         <li><a href="https://discuss.grapheneos.org/">Forum</a></li>
         <li><a href="https://discord.com/invite/grapheneos">Discord</a></li>