add logo art designer

Author: kazupon

.vitepress/theme/Info.vue

@@ -6,5 +6,8 @@
     <p class="text-white text-center">
       {{ $frontmatter.copyright }}
     </p>
+    <p class="text-white text-center">
+      Logo art designed by <a href="https://www.ceroan.co.jp/" aria-label="ceroan LLC" target="_blank">ceroan LLC</a>
+    </p>
   </section>
 </template>