✅ How to use ResourceDictionary in the App.xaml?

 xaml
    <DataTemplate DataType="{x:Type vm:TweaksVM}">
        <view:Tweaks />
    </DataTemplate>

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:view="clr-namespace:WinRep_Code.Views"
                    xmlns:vm="clr-namespace:WinRep_Code.ViewModels">

C:.
│   App.xaml
│   App.xaml.cs
│   AssemblyInfo.cs
│   WinRep-Code.csproj
│   WinRep-Code.csproj.user
│   WinRep-Code.sln
│
├───Utilities
│       BaseViewModel.cs
│       DataTemplate.xaml
│       NavigationService.cs
│       RelayCommand.cs
│
├───ViewModels
│       CustomTweaksVM.cs
│       InstallVM.cs
│       MainWindowVM.cs
│       ScanSettingsVM.cs
│       ScanVM.cs
│       TweaksVM.cs
│
└───Views
        CustomTweaks.xaml
        Install.xaml
        MainWindow.xaml
        Scan.xaml
        ScanSettings.xaml
        Tweaks.xaml