fix typo

Author: dankoman30

src/MahApps.Metro/Styles/Themes/Theme.Template.xaml

@@ -7,7 +7,7 @@
                     xmlns:system="clr-namespace:System;assembly=mscorlib"
                     mc:Ignorable="options">
 
-    <!--  Matadata  -->
+    <!--  Metadata  -->
     <system:String x:Key="Theme.Name">{{ThemeName}}</system:String>
     <system:String x:Key="Theme.Origin">MahApps.Metro</system:String>
     <system:String x:Key="Theme.DisplayName">{{ThemeDisplayName}}</system:String>
@@ -559,4 +559,4 @@
     <markup:StaticResource x:Key="MahApps.Brushes.ToggleSwitch.KnobFillOnPressed" ResourceKey="MahApps.Brushes.SystemControlHighlightAltChromeWhite" />
     <markup:StaticResource x:Key="MahApps.Brushes.ToggleSwitch.KnobFillOnDisabled" ResourceKey="MahApps.Brushes.SystemControlPageBackgroundBaseLow" />
 
-</ResourceDictionary>
+</ResourceDictionary>