Merge pull request #1416 from syncfusion-content/1027486_Review_Suggestions_WINUI

1027486-Ensure Live UG Updates and Address Review Suggestions for WinUI charts

Author: SaiyathAliFathima

winui/Cartesian-Charts/Stacked.md

@@ -188,7 +188,7 @@ The [StackedAreaSeries](https://help.syncfusion.com/cr/winui/Syncfusion.UI.Xaml.
     </chart:SfCartesianChart.XAxes>
 
     <chart:SfCartesianChart.YAxes>
-        <chart:NumericalAxis />
+        <chart:NumericalAxis/>
     </chart:SfCartesianChart.YAxes>
 
     <chart:StackedAreaSeries 

winui/Cartesian-Charts/Stacked100.md

@@ -106,7 +106,7 @@ The [StackedLine100Series](https://help.syncfusion.com/cr/winui/Syncfusion.UI.Xa
     </chart:SfCartesianChart.XAxes>
 
     <chart:SfCartesianChart.YAxes>
-        <chart:NumericalAxis />
+        <chart:NumericalAxis/>
     </chart:SfCartesianChart.YAxes>
 
     <chart:StackedLine100Series 

winui/Polar-Chart/Legend.md

@@ -272,11 +272,11 @@ The legend background appearance can be customized by using the following proper
 
 <chart:SfPolarChart>
     <chart:SfPolarChart.Legend>
-        <chart:ChartLegend                 
+        <chart:ChartLegend
             Background="LightGray"
-                        BorderBrush="Black" 
-                           BorderThickness="1" 
-                           CornerRadius="5">
+            BorderBrush="Black"
+            BorderThickness="1"
+            CornerRadius="5">
         </chart:ChartLegend>
     </chart:SfPolarChart.Legend>
     ...