Correcting the ArgumentNullException.xml string constructor example text (dotnet#7423)

Author: martinstenhoff

xml/System/ArgumentNullException.xml

@@ -191,7 +191,7 @@
 |Property|Value|  
 |--------------|-----------|  
 |<xref:System.Exception.InnerException%2A>|A null reference (`Nothing` in Visual Basic).|  
-|<xref:System.ArgumentException.Message%2A>|A localized error message string that identifies the null argument. For example, if the `paramName` argument is "arg1", the English language message string is:<br /><br /> `Value cannot be null.Parameter name: arg01`|  
+|<xref:System.ArgumentException.Message%2A>|A localized error message string that identifies the null argument. For example, if the `paramName` argument is "arg1", the English language message string is:<br /><br />On .NET 5+ and .NET Core: `Value cannot be null. (Parameter name: 'arg1')`<br /><br />On .NET Framework: `Value cannot be null.\r\nParameter name: arg1`|  
 |<xref:System.ArgumentException.ParamName%2A>|The parameter name string.|  
   
  ]]></format>