Update readme and fix UWP package for older version of W10

Author: roubachof

README.md

@@ -21,6 +21,9 @@ On `iOS` add this line after `Xamarin.Forms.Forms.Init()` and before `LoadApplic
 
 `Sharpnado.Shades.iOS.iOSShadowsRenderer.Initialize();`
 
+In `UWP`, you must register the renderers assembly like this, before `Xamarin.Forms.Forms.Init()`:
+
+`var rendererAssemblies = new[] { typeof(UWPShadowsRenderer).GetTypeInfo().Assembly }; `
 
 On `Tizen` add this line after `Xamarin.Forms.Forms.Init()` and before `LoadApplication(new App())`.
 

Shadows/Shadows.UWP/UWPShadowsController.cs

@@ -159,7 +159,7 @@ private void ShadowSourceSizeChanged(object sender, SizeChangedEventArgs e)
 
             InternalLogger.Debug(
                 LogTag,
-                $"shadowSource: {{ ActualOffset: {_shadowSource.ActualOffset}, ActualSize: {_shadowSource.ActualSize}, Margin: {_shadowSource.Margin} }}");
+                () => $"shadowSource: {{ Offset: {offset}, Size: {width}x{height}, Margin: {_shadowSource.Margin} }}");
 
             for (int i = 0; i < _shadesSource.Count(); i++)
             {
@@ -168,7 +168,8 @@ private void ShadowSourceSizeChanged(object sender, SizeChangedEventArgs e)
 
                 InternalLogger.Debug(
                     LogTag,
-                    $"shadowHost: {{ ActualOffset: {shadowHost.ActualOffset}, ActualSize: {shadowHost.ActualSize}, Margin: {shadowHost.Margin} }}");
+                    () => $"shadowHost: {{ Size: {shadowHost.ActualWidth}x{shadowHost.ActualHeight}, Margin: {shadowHost.Margin} }}");
+
                 Canvas.SetLeft(shadowHost, offset.X + SafeMargin);
                 Canvas.SetTop(shadowHost, offset.Y + SafeMargin);
 

Sharpnado.Shadows.nuspec

@@ -32,6 +32,11 @@ Mandatory initialization on iOS:
     Xamarin.Forms.Forms.Init();
     Sharpnado.Shades.iOS.iOSShadowsRenderer.Initialize();
 
+Mandatory initialization on UWP:
+
+    var rendererAssemblies = new[] { typeof(UWPShadowsRenderer).GetTypeInfo().Assembly };
+    Xamarin.Forms.Forms.Init(e, rendererAssemblies);
+
 Mandatory initialization on Tizen:
 
     Xamarin.Forms.Forms.Init();