Update SqlFacetAttribute.xml to indicate possible usage on input parameters (#4477)

Author: allmhuran

xml/Microsoft.SqlServer.Server/SqlFacetAttribute.xml

@@ -34,7 +34,9 @@
       <format type="text/markdown"><![CDATA[  
   
 ## Remarks  
- <xref:Microsoft.SqlServer.Server.SqlFacetAttribute> may only be specified on non-void return values.  
+ <xref:Microsoft.SqlServer.Server.SqlFacetAttribute> can only be specified on non-void return values or on input parameters. 
+
+To specify the <xref:Microsoft.SqlServer.Server.SqlFacetAttribute> on an input parameter, add the decoration inline with the parameter.
   
  <xref:Microsoft.SqlServer.Server.SqlFacetAttribute> is used only to derive information about the return type, and is not intended to be a constraint specification on what can be stored in the type. Thus, if a field has a <xref:Microsoft.SqlServer.Server.SqlFacetAttribute> indicating its size to be 2 characters, then the SQL Server type of the field access expression is of size 2, but assignments into the field are not restricted by this facet.