Move Settings link into the user profile dropdown

Settings was still a top-level navbar item; per feedback it belongs in
the profile dropdown instead, above Sign out. The navbar now only shows
Inventory for everyone.

web/templates/layout.html

@@ -19,9 +19,6 @@
     <div class="collapse navbar-collapse" id="navMain">
       <ul class="navbar-nav me-auto">
         <li class="nav-item"><a class="nav-link" href="/inventory">Inventory</a></li>
-        {{if .User.IsAdmin}}
-        <li class="nav-item"><a class="nav-link" href="/settings">Settings</a></li>
-        {{end}}
       </ul>
       <ul class="navbar-nav">
         <li class="nav-item dropdown">
@@ -30,6 +27,10 @@
             {{if .User.IsAdmin}}<span class="badge text-bg-secondary ms-1">admin</span>{{end}}
           </a>
           <ul class="dropdown-menu dropdown-menu-end">
+            {{if .User.IsAdmin}}
+            <li><a class="dropdown-item" href="/settings"><i class="bi bi-gear me-2"></i>Settings</a></li>
+            <li><hr class="dropdown-divider"></li>
+            {{end}}
             <li>
               <form action="/logout" method="post" class="px-3 py-1">
                 <button type="submit" class="btn btn-sm btn-outline-secondary w-100">Sign out</button>