Automatically port System.Text.Json documentation (#3795)

* Automatically port System.Text.Json documentation

* Reset remark

Author: carlossanlop

xml/System.Text.Json/JsonSerializer.xml

@@ -517,6 +517,8 @@ For more information, see [How to serialize and deserialize JSON](~/docs/standar
 
           ]]></format>
         </remarks>
+        <exception cref="T:System.ArgumentNullException">
+          <paramref name="writer" /> is <see langword="null" />.</exception>
       </Docs>
     </Member>
     <Member MemberName="Serialize&lt;TValue&gt;">
@@ -600,6 +602,8 @@ For more information, see [How to serialize and deserialize JSON](~/docs/standar
 
           ]]></format>
         </remarks>
+        <exception cref="T:System.ArgumentNullException">
+          <paramref name="writer" /> is <see langword="null" />.</exception>
       </Docs>
     </Member>
     <Member MemberName="SerializeAsync">