fixed faulty links to the source in the MD3 demo app (#3836)

Author: corvinsz

src/MaterialDesign3.Demo.Wpf/Domain/DocumentationLink.cs

@@ -25,7 +25,7 @@ public static DocumentationLink WikiLink(string page, string label)
 
     public static DocumentationLink StyleLink(string nameChunk, bool isMd3Style = false)
     {
-        var themesUrl = $"{ConfigurationManager.AppSettings["GitHub"]}/blob/master/MaterialDesignThemes.Wpf/Themes/";
+        var themesUrl = $"{ConfigurationManager.AppSettings["GitHub"]}/blob/master/src/MaterialDesignThemes.Wpf/Themes/";
 
         return new DocumentationLink(
             DocumentationLinkType.StyleSource,
@@ -39,7 +39,7 @@ public static DocumentationLink ApiLink<TClass>(string subNamespace)
 
         return new DocumentationLink(
             DocumentationLinkType.ControlSource,
-            $"{ConfigurationManager.AppSettings["GitHub"]}/blob/master/MaterialDesignThemes.Wpf/{subNamespace}/{typeName}.cs",
+            $"{ConfigurationManager.AppSettings["GitHub"]}/blob/master/src/MaterialDesignThemes.Wpf/{subNamespace}/{typeName}.cs",
             typeName);
     }
 
@@ -53,7 +53,7 @@ public static DocumentationLink ApiLink(Type type)
 
         return new DocumentationLink(
             DocumentationLinkType.ControlSource,
-            $"{ConfigurationManager.AppSettings["GitHub"]}/blob/master/MaterialDesignThemes.Wpf/{typeName}.cs",
+            $"{ConfigurationManager.AppSettings["GitHub"]}/blob/master/src/MaterialDesignThemes.Wpf/{typeName}.cs",
             typeName);
     }