Add tensor doc page with link to dpctl 0.21.1 API reference

Author: vlad-perevezentsev

doc/index.rst

@@ -13,6 +13,7 @@ Data Parallel Extension for NumPy*
    overview
    quick_start_guide
    reference/index
+   tensor
 
 .. toctree::
    :maxdepth: 1

doc/tensor.rst

@@ -0,0 +1,18 @@
+.. _tensor:
+
+Tensor (``dpnp.tensor``)
+========================
+
+``dpnp.tensor`` provides a reference implementation of the
+`Python Array API <https://data-apis.org/array-api/latest/>`_ specification. The implementation
+uses data-parallel algorithms suitable for execution on accelerators, such as GPUs.
+
+``dpnp.tensor`` is written using C++ and `SYCL <https://registry.khronos.org/SYCL/specs/sycl-2020/html/sycl-2020.html>`_
+and oneAPI extensions implemented in `Intel(R) oneAPI DPC++ compiler <https://www.intel.com/content/www/us/en/developer/tools/oneapi/dpc-compiler.html>`_.
+
+.. note::
+
+   The documentation for ``dpnp.tensor`` API documentation will be added in a future release.
+
+   For the complete API reference, see the
+   `dpctl 0.21.1 tensor documentation <https://intelpython.github.io/dpctl/0.21.1/api_reference/dpctl/tensor.html>`_.