feat(ui): 顶栏添加 GitHub 跳转按钮

src/TelegramPanel.Web/Components/Layout/MainLayout.razor

@@ -10,6 +10,12 @@
         <MudIconButton Icon="@Icons.Material.Filled.Menu" Color="Color.Inherit" Edge="Edge.Start" OnClick="@ToggleDrawer" />
         <MudText Typo="Typo.h5" Class="ml-3">Telegram Panel</MudText>
         <MudSpacer />
+        <MudIconButton Icon="@Icons.Custom.Brands.GitHub"
+                       Color="Color.Inherit"
+                       Href="https://github.com/moeacgx/Telegram-Panel"
+                       Target="_blank"
+                       Rel="noopener noreferrer"
+                       title="GitHub" />
         <MudIconButton Icon="@(_isDarkMode ? Icons.Material.Filled.LightMode : Icons.Material.Filled.DarkMode)"
                        Color="Color.Inherit"
                        OnClick="@ToggleDarkMode" />