Update README.md

Author: RikshaDriver

README.md

@@ -1,8 +1,21 @@
 # add_cuda_path
 
-Script to add CUDA PATH directories
+Script to add CUDA PATH variables directories at the system level.
 
-Tested on Ubuntu 18.04
+The profile script allows CUDA environment variables to be enabled for all users.
 
-# Usage
-Add shell script to /etc/profile.d/ as root
+Tested on Ubuntu 18.04, but should work on other Linux instances.
+
+## Installation
+It's recommended to create a symbolic link from the desired CUDA directory to /usr/local/cuda.
+
+Example:
+> ln -sf /usr/local/cuda-10.2 /usr/local/cuda
+
+The script looks for a CUDA installation under /usr/local/cuda
+
+For multiple CUDA installations, simply update the symbolic link to point towards the desired CUDA version.
+
+Copy the shell script to /etc/profile.d/ as root
+
+> sudo cp cuda.sh /etc/profile.d/