update readme in doc menu-0.15.0

test=release/0.15.0

doc/README.md

@@ -2,6 +2,6 @@
 
 Thanks for reading PaddlePaddle documentation.
 
-Since **September 17th, 2018**, the **0.15.0 and develop** documentation source has been moved to [Fluiddoc Repo](https://github.com/PaddlePaddle/Paddle) and updated in Fluiddoc Repo.
+Since **September 17th, 2018**, the **0.15.0 and develop** documentation source has been moved to [FluidDoc Repo](https://github.com/PaddlePaddle/FluidDoc) and updated there.
 
-Please turn to Fluiddoc Repo for the latest documentation.
+Please turn to FluidDoc Repo for the latest documentation.