Clarify SYCL target selection and add CUDA/AMD/Multi-target subchapters

Author: vlad-perevezentsev

docs/doc_sources/beginners_guides/installation.rst

@@ -159,6 +159,13 @@ The following plugins from CodePlay are supported:
 .. _codeplay_nv_plugin: https://developer.codeplay.com/products/oneapi/nvidia/
 .. _codeplay_amd_plugin: https://developer.codeplay.com/products/oneapi/amd/
 
+Builds for CUDA and AMD devices internally use SYCL alias targets that are passed to the compiler.
+A full list of available SYCL alias targets is available in the
+`DPC++ Compiler User Manual <https://intel.github.io/llvm/UsersManual.html>`_.
+
+CUDA build
+~~~~~~~~~~
+
 ``dpctl`` can be built for CUDA devices using the ``DPCTL_TARGET_CUDA`` CMake option,
 which accepts a specific compute architecture string:
 
@@ -173,19 +180,20 @@ set ``DPCTL_TARGET_CUDA`` to a value such as ``ON``, ``TRUE``, ``YES``, ``Y``, o
 
     python scripts/build_locally.py --verbose --cmake-opts="-DDPCTL_TARGET_CUDA=ON"
 
-Note that kernels are built for ``sm_50`` by default, allowing them to work on a wider
-range of architectures, but limiting the usage of more recent CUDA features.
+Note that kernels are built for the default architecture (``sm_50``), allowing them to work on a
+wider range of architectures, but limiting the usage of more recent CUDA features.
 
 For reference, compute architecture strings like ``sm_80`` correspond to specific
 CUDA Compute Capabilities (e.g., Compute Capability 8.0 corresponds to ``sm_80``).
 A complete mapping between NVIDIA GPU models and their respective
 Compute Capabilities can be found in the official
 `CUDA GPU Compute Capability <https://developer.nvidia.com/cuda-gpus>`_ documentation.
 
-A full list of available SYCL alias targets is available in the
-`DPC++ Compiler User Manual <https://intel.github.io/llvm/UsersManual.html>`_.
+AMD build
+~~~~~~~~~
 
-To build for AMD devices, use:
+``dpctl`` can be built for AMD devices using the ``DPCTL_TARGET_HIP`` CMake option,
+which requires specifying a compute architecture string:
 
 .. code-block:: bash
 
@@ -194,8 +202,13 @@ To build for AMD devices, use:
 Note that the  `oneAPI for AMD GPUs` plugin requires the architecture be specified and only
 one architecture can be specified at a time.
 
-It is, however, possible to build for Intel devices, CUDA devices, and an AMD device
-architecture all at once:
+Multi-target build
+~~~~~~~~~~~~~~~~~~
+
+The default ``dpctl`` build from the source enables support of Intel devices only.
+Extending the build with a custom SYCL target additionally enables support of CUDA or AMD
+device in ``dpctl``. Besides, the support can be also extended to enable both CUDA and AMD
+devices at the same time:
 
 .. code-block:: bash