Fix typo in KeyConveter ctor sumary (#10286)

Author: rzikm

xml/System.Windows.Input/KeyConverter.xml

@@ -56,7 +56,7 @@
       </Attributes>
       <Parameters />
       <Docs>
-        <summary>Initializes a new instance of the <see cref="T:System.Windows.Input.Key" /> class.</summary>
+        <summary>Initializes a new instance of the <see cref="T:System.Windows.Input.KeyConverter" /> class.</summary>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>