feat(frontend+backend): add theming to the blazor frontend

frontend/Components/Layout/MainLayout.razor

@@ -1,15 +1,11 @@
 @inherits LayoutComponentBase
 
 <div class="page">
-    <div class="sidebar">
+    <div class="sidebar nimbus-sidebar">
         <NavMenu />
     </div>
 
     <main>
-        <div class="top-row px-4">
-            <a href="https://learn.microsoft.com/aspnet/core/" target="_blank">About</a>
-        </div>
-
         <article class="content px-4">
             @Body
         </article>

frontend/Components/Layout/NavMenu.razor

@@ -1,6 +1,8 @@
 <div class="top-row ps-3 navbar navbar-dark">
     <div class="container-fluid">
-        <a class="navbar-brand" href="">NimbusFlow</a>
+        <a class="navbar-brand" href="">
+            <i class="bi bi-cloud nimbus-brand-icon" aria-hidden="true"></i>NimbusFlow
+        </a>
     </div>
 </div>
 
@@ -8,27 +10,27 @@
 
 <div class="nav-scrollable" onclick="document.querySelector('.navbar-toggler').click()">
     <nav class="flex-column">
-        <div class="nav-item px-3">
+        <div class="nav-item">
             <NavLink class="nav-link" href="" Match="NavLinkMatch.All">
-                <span class="bi bi-house-door-fill-nav-menu" aria-hidden="true"></span> Dashboard
+                <i class="bi bi-house-door-fill me-2" aria-hidden="true"></i> Dashboard
             </NavLink>
         </div>
 
-        <div class="nav-item px-3">
+        <div class="nav-item">
             <NavLink class="nav-link" href="members">
-                <span class="bi bi-people-fill-nav-menu" aria-hidden="true"></span> Members
+                <i class="bi bi-people-fill me-2" aria-hidden="true"></i> Members
             </NavLink>
         </div>
 
-        <div class="nav-item px-3">
+        <div class="nav-item">
             <NavLink class="nav-link" href="schedules">
-                <span class="bi bi-calendar-event-fill-nav-menu" aria-hidden="true"></span> Schedules
+                <i class="bi bi-calendar-event-fill me-2" aria-hidden="true"></i> Schedules
             </NavLink>
         </div>
 
-        <div class="nav-item px-3">
+        <div class="nav-item">
             <NavLink class="nav-link" href="services">
-                <span class="bi bi-calendar-plus-fill-nav-menu" aria-hidden="true"></span> Services
+                <i class="bi bi-calendar-plus-fill me-2" aria-hidden="true"></i> Services
             </NavLink>
         </div>
     </nav>