update README

Author: leofang

cuda_core/README.md

@@ -1,9 +1,9 @@
-# `cuda.py`: (experimental) pythonic CUDA module
+# `cuda.core`: (experimental) pythonic CUDA module
 
 Currently under active development. To build from source, just do:
 ```shell
 $ git clone -b cuda_py https://github.com/NVIDIA/cuda-python
-$ cd cuda-python/cuda_py  # move to the directory where this README locates
+$ cd cuda-python/cuda_core  # move to the directory where this README locates
 $ pip install .
 ```
 For now `cuda-python` is a required dependency.