fixed bad paramref

Author: Ron Petrusha

xml/System.Text.Json/JsonEncodedText.xml

@@ -60,7 +60,7 @@ This type can be used to cache and store known strings used for writing JSON ahe
         <summary>Encodes a UTF-8 encoded byte span as a JSON string.</summary>
         <returns>The JSON string.</returns>
         <remarks>To be added.</remarks>
-        <exception cref="T:System.ArgumentException"><paramref name'utf8Value" /> is too large or contains invalid UTF-8 bytes.</exception>
+        <exception cref="T:System.ArgumentException"><paramref name="utf8Value" /> is too large or contains invalid UTF-8 bytes.</exception>
       </Docs>
     </Member>
     <Member MemberName="Encode">