add @gist for README

Author: lintianzhi

qiniu/io.js

@@ -16,12 +16,14 @@ exports.putWithoutKey = putWithoutKey;
 exports.putFile = putFile;
 exports.putFileWithoutKey = putFileWithoutKey;
 
+// @gist PutExtra
 function PutExtra(params, mimeType, crc32, checkCrc) {
   this.paras = params || {};
   this.mimeType = mimeType || null;
   this.crc32 = crc32 || null;
   this.checkCrc = checkCrc || 0;
 }
+// @endgist
 
 function PutRet(hash, key) {
   this.hash = hash || null;

qiniu/rs.js

@@ -162,7 +162,7 @@ function getEncodedEntryUri(bucket, key) {
 
 
 // ----- token --------
-
+// @gist PutPolicy
 function PutPolicy(scope, callbackUrl, callbackBody, returnUrl, returnBody,
                   asyncOps, endUser, expires) {
   this.scope = scope || null;
@@ -174,6 +174,7 @@ function PutPolicy(scope, callbackUrl, callbackBody, returnUrl, returnBody,
   this.endUser = endUser || null;
   this.expires = expires || 3600;
 }
+// @endgist
 
 PutPolicy.prototype.token = function(mac) {
   if (mac == null) {