Update README.md

Author: wkh237

README.md

@@ -127,9 +127,7 @@ HTTP request destination url.
 #### headers:`object` (Optional)
 Headers of HTTP request, value of headers should be `stringified`, if you're uploading binary files, content-type should be `application/octet-stream` or `multipart/form-data`(see examples above).
 #### body:`string | Array<Object>` (Optional)
-Body of the HTTP request, body can either be a BASE64 string, or an array contains object elements, each element should use the following format.
-
-
+Body of the HTTP request, body can either be a BASE64 string, or an array contains object elements, each element have 2  required property `name`, and `data`, and 1 optional property `filename`, once `filename` is set, content in `data` property will be consider as BASE64 string that will be converted into byte array later.
 
 When body is a base64 string , this string will be converted into byte array in native code, and the request body will be sent as `application/octet-stream`.