[docs] Fix runtime feature detection documentation (#16746)

* add runtime docs

* Add example for documentation

* Fix lint

docs/python_docs/python/api/mxnet/index.rst

@@ -40,6 +40,7 @@ mxnet
     mxnet.kvstore
     mxnet.kvstore_server
     mxnet.libinfo
+    mxnet.runtime
     mxnet.lr_scheduler
     mxnet.log
     mxnet.metric
@@ -70,4 +71,4 @@ mxnet
    :maxdepth: 2
    :glob:
 
-   */index
+   */index

docs/python_docs/python/api/mxnet/runtime/index.rst

@@ -0,0 +1,23 @@
+.. Licensed to the Apache Software Foundation (ASF) under one
+   or more contributor license agreements.  See the NOTICE file
+   distributed with this work for additional information
+   regarding copyright ownership.  The ASF licenses this file
+   to you under the Apache License, Version 2.0 (the
+   "License"); you may not use this file except in compliance
+   with the License.  You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing,
+   software distributed under the License is distributed on an
+   "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+   KIND, either express or implied.  See the License for the
+   specific language governing permissions and limitations
+   under the License.
+
+mxnet.runtime
+===============
+
+.. automodule:: mxnet.runtime
+    :members:
+    :autosummary:

python/mxnet/runtime.py

@@ -19,7 +19,32 @@
 
 # pylint: disable=not-an-iterable
 
-"""runtime querying of compile time features in the native library"""
+"""Runtime querying of compile time features in the native library.
+
+With this module you can check at runtime which libraries and features were compiled in the library.
+
+Example usage:
+
+.. code-block:: python
+
+    import mxnet
+    features=mxnet.runtime.Features()
+
+    features.is_enabled("CUDNN")
+    False
+
+    features.is_enabled("CPU_SSE")
+    True
+
+    print(features)
+    [✖ CUDA, ✖ CUDNN, ✖ NCCL, ✖ CUDA_RTC, ✖ TENSORRT, ✔ CPU_SSE, ✔ CPU_SSE2, ✔ CPU_SSE3,
+    ✔ CPU_SSE4_1, ✔ CPU_SSE4_2, ✖ CPU_SSE4A, ✔ CPU_AVX, ✖ CPU_AVX2, ✔ OPENMP, ✖ SSE,
+    ✔ F16C, ✔ JEMALLOC, ✔ BLAS_OPEN, ✖ BLAS_ATLAS, ✖ BLAS_MKL, ✖ BLAS_APPLE, ✔ LAPACK,
+    ✖ MKLDNN, ✔ OPENCV, ✖ CAFFE, ✖ PROFILER, ✖ DIST_KVSTORE, ✖ CXX14, ✖ INT64_TENSOR_SIZE,
+    ✔ SIGNAL_HANDLER, ✔ DEBUG, ✖ TVM_OP]
+
+
+"""
 
 import ctypes
 import collections