Merge pull request #119 from PaddlePaddle/fix_model_softlink

fix models' softlink

doc/fluid/user_guides/index.rst

@@ -16,5 +16,5 @@
     howto/debug/index
     howto/evaluation/index
     howto/inference/index
-    models/index.md
+    models/index.rst
     design_idea/fluid_design_idea.md

doc/fluid/user_guides/models/index.md

-../../../../external/models/fluid/README.md
\ No newline at end of file

doc/fluid/user_guides/models/index.rst

+../../../../external/models/fluid/README.cn.rst
\ No newline at end of file