feat(windows): add support for 74 and bump Example (#2315)

Added support for RNW 74.
Bumped windows Example to 74.
Updated README.md to remove instructions on how to import Win2D since we no longer use it.

windows/RNSVG/RenderableViewManager.cpp

@@ -44,6 +44,8 @@ xaml::FrameworkElement RenderableViewManager::CreateView() {
       return winrt::RNSVG::ClipPathView();
     case RNSVG::SVGClass::RNSVGMarker:
       return winrt::RNSVG::MarkerView();
+    case RNSVG::SVGClass::RNSVGMask:
+      return winrt::RNSVG::MaskView();
   }
 
   throw hresult_not_implemented();