update by comment

Yancey0623 · Yancey0623 · commit 302136e09a7b · 2018-03-14T23:57:31.000+08:00
diff --git a/doc/fluid/design/dist_train/prefetch_parameter.md b/doc/fluid/design/dist_train/prefetch_parameter.md
@@ -1,4 +1,4 @@
-# Design Doc: Prefecting Parameter From Parameter Server
+# Design Doc: Prefetching Parameter From Parameter Server
 
 ## Abstract
 

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-# Design Doc: Prefecting Parameter From Parameter Server`
	`1`	`+# Design Doc: Prefetching Parameter From Parameter Server`
`2`	`2`
`3`	`3`	`## Abstract`
`4`	`4`