Update index.html

Author: NovaDev404

web/index.html

@@ -11,7 +11,7 @@
         <div class="sidebar">
           <div onclick="window.location.href = 'index.html';" class="sidebar-item active">ProStore Installer</div>
           <div onclick="window.location.href = 'cert.html';" class="sidebar-item">Certificate Manager</div>
-          <div onclick="window.location.href = 'converter.html';" class="sidebar-item">Certificate Converter</div>
+          <div onclick="window.location.href = 'guide.html';" class="sidebar-item">Guide</div>
         </div>
 
         <div class="panel">