fix(website): replace checkmark logo with lightning bolt

Author: bobberdolle1

website/src/components/Navbar.astro

@@ -7,7 +7,7 @@
     <a href="/" class="nav-logo">
       <svg class="logo-mark" width="20" height="20" viewBox="0 0 20 20" fill="none">
         <rect x="1" y="1" width="18" height="18" rx="5" stroke="currentColor" stroke-width="1.5"/>
-        <path d="M7 10L9 12L13 8" stroke="currentColor" stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round"/>
+        <path d="M11.5 3.5L5.5 11.5H10.5L9 16.5L15 8.5H10L11.5 3.5Z" fill="currentColor" stroke="currentColor" stroke-width="1" stroke-linejoin="round"/>
       </svg>
       <span class="logo-text">UNBOUND</span>
     </a>