readme formatting

README.adoc

@@ -410,7 +410,8 @@ These extra headers will then be returned as part of the response.
 
 These extra headers are part of a 4th encoded url path component, signed under the hmac signature.
 
-The underlying data is a json dict/map of an array of header values (since a given http header can be present with multiple values). Example:
+The underlying data is a json dict/map of string values. +
+Example:
 ----
 {
  "content-disposition": "attachment; filename=\"image.png\""