[lang] Add language guide

Signed-off-by: Jay Gu <jagu@nvidia.com>

Author: haijieg

experimental/cuda-lang/docs/source/_templates/doctest/language_example.py

@@ -0,0 +1,9 @@
+import cuda.lang as cl
+import torch
+
+torch.cuda.init()
+stream = torch.cuda.current_stream()
+
+{{body}}
+
+torch.cuda.synchronize()

experimental/cuda-lang/docs/source/index.rst

@@ -71,6 +71,7 @@ memory:
    :maxdepth: 2
    :hidden:
 
+   language
    data
    operations
    private