add comment for emitUTF8 in header
diff --git a/include/json/writer.h b/include/json/writer.h
index fb0852a..99d74c7 100644
--- a/include/json/writer.h
+++ b/include/json/writer.h
@@ -110,6 +110,8 @@
* - Number of precision digits for formatting of real values.
* - "precisionType": "significant"(default) or "decimal"
* - Type of precision for formatting of real values.
+ * - "emitUTF8": false or true
+ * - If true, outputs raw UTF8 strings instead of escaping them.
* You can examine 'settings_` yourself
* to see the defaults. You can also write and read them just like any