Documenting the torch.cuda.nccl.version function (pytorch#128022)

Fixes pytorch#127892

This PR adds docstring to the torch.cuda.nccl.version function

Pull Request resolved: pytorch#128022
Approved by: https://github.com/malfet

torch/cuda/nccl.py

@@ -32,6 +32,15 @@ def is_available(tensors):
 
 
 def version():
+    """
+    Returns the version of the NCCL.
+
+
+    This function returns a tuple containing the major, minor, and patch version numbers of the NCCL.
+    The suffix is also included in the tuple if a version suffix exists.
+    Returns:
+        tuple: The version information of the NCCL.
+    """
     ver = torch._C._nccl_version()
     major = ver >> 32
     minor = (ver >> 16) & 65535