[Nano] Integrate ipynb files into ReadtheDocs (#5222)

* Add nbsphinx extension for docs

* Add specific ipynb files to readthedocs folder and add links to Nano Tutorials index page

* Disable execution of ipynb notebook

* Remove outputs of two ipynb files

* Rename titles and add navigation texts to seq_and_func.ipynb under readthedocs folder

* Rename titles and add navigation texts to custom.ipynb file under readthedocs folder

docs/readthedocs/requirements-doc.txt

@@ -11,7 +11,7 @@ cloudpickle==2.1.0
 ray[tune]==1.9.2
 ray==1.9.2
 torch==1.9.0
-Pygments==2.3.1
+Pygments==2.6.1
 setuptools==41.0.1
 docutils==0.17
 mock==1.0.1
@@ -36,4 +36,5 @@ sphinx-tabs==3.4
 optuna==2.10.0
 ConfigSpace==0.5.0
 sphinx-design==0.2.0
-sphinx-external-toc==0.3.0
+sphinx-external-toc==0.3.0
+nbsphinx==0.8.9

docs/readthedocs/source/conf.py

@@ -92,6 +92,7 @@ extensions = [
     'sphinx_tabs.tabs',
     'sphinx_design',
     'sphinx_external_toc',
+    'nbsphinx'
 ]
 
 
@@ -244,3 +245,6 @@ def setup(app):
         'enable_auto_doc_ref': True,
     }, True)
     app.add_transform(AutoStructify)
+
+# disable notebook execution
+nbsphinx_execute = 'never'

docs/readthedocs/source/doc/Nano/QuickStart/index.md

@@ -48,9 +48,7 @@
 
 ---------------------------
 
-
-- [**BigDL-Nano Hyperparameter Tuning (Tensorflow Sequential/Functional API) Quickstart**](./pytorch_quantization_openvino.html)
-
+- [**BigDL-Nano Hyperparameter Tuning (Tensorflow Sequential/Functional API) Quickstart**](../Tutorials/seq_and_func.html)
 
     > ![](../../../../image/colab_logo_32px.png)[Run in Google Colab][Nano_hpo_tf_seq_func_colab]  ![](../../../../image/GitHub-Mark-32px.png)[View source on GitHub][Nano_hpo_tf_seq_func]
 
@@ -60,7 +58,7 @@
 
 ---------------------------
 
-- [**BigDL-Nano Hyperparameter Tuning (Tensorflow Subclassing Model) Quickstart**](./pytorch_quantization_openvino.html)
+- [**BigDL-Nano Hyperparameter Tuning (Tensorflow Subclassing Model) Quickstart**](../Tutorials/custom.html)
 
     > ![](../../../../image/colab_logo_32px.png)[Run in Google Colab][Nano_hpo_tf_subclassing_colab]  ![](../../../../image/GitHub-Mark-32px.png)[View source on GitHub][Nano_hpo_tf_subclassing]