[Example] Update cpp example README

cpp-package/example/README.md

@@ -16,6 +16,7 @@ By default, the examples are built to be run on GPU. To build examples to run on
 
 The examples that are built to be run on GPU may not work on the non-GPU machines.
 The makefile will also download the necessary data files and store in a data folder. (The download will take couple of minutes, but will be done only once on a fresh installation.)
+Before runing examples, make sure **LD\_LIBRARY\_PATH** environment variable setup correctly. For example `export LD_LIBRARY_PATH=/usr/local/cuda/lib64:/home/ubuntu/incubator-mxnet/lib` on ubuntu using gpu.
 
 
 ## Examples
@@ -26,9 +27,9 @@ This directory contains following examples. In order to run the examples, ensure
 
 The example implements the C++ version of AlexNet. The networks trains on MNIST data. The number of epochs can be specified as a command line argument. For example to train with 10 epochs use the following:
 
-	```
-	build/alexnet 10
-	```
+```
+build/alexnet 10
+```
 
 ### [googlenet.cpp](<https://github.com/apache/incubator-mxnet/blob/master/cpp-package/example/googlenet.cpp>)