* Update open in colab button from HTML-style hyperlinks to markdown image with link for notebooks in readthedocs folder
* Update "Open in Colab" button for notebooks under python folder with markdown image with link
* Add tutorial notebook
* Add md
* Test on readthedocs
* Fix markdown
* fix md
* update notebooks
* update requirements version in doc
* update
* add and update tutorial
* add unit test for tensorflow tutorial
* reduce test time
* reduce test time
* update shell
* update action
* Update tutorial
* reduce ut time
* reduce ut time
* reduce ut time
* reduce ut time
* reduce ut time
* Update
* Fix shell
* update
* update
* rollback requirements
* Update
* Update
Co-authored-by: pinggao187 <ping.gao3@pactera.com>
* Correct typos for Nano User Guide page
* Correct typos for BigDL-Nano PyTorch Training Overview page
* Correct typos for BigDL-Nano PyTorch Inference Overview page
* Correct typos for BigDL-Nano PyTorch ONNXRuntime Acceleration Quickstart page
* Correct typos for Windows User Guide page
* Correct typos for BigDL-Nano TensorFlow Training Overview page
* Correct typos for BigDL-Nano TensorFlow Inference Overview page
* Small fix based on Shengsheng's comments
* Fix based on Wang, Yang's comments
* 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
* Add nano documentation for pytorch training quickstart
* fix some typo
* break pytorch training and inference to two files
* simplify trainer import
* fix train doc