Polish Orca Doc (#6266)

* fix doc

* add tutorial index

* remove

* fix

* remove

* update

docs/readthedocs/source/_toc.yml

@@ -26,7 +26,7 @@ subtrees:
       subtrees:
         - entries:
           - file: doc/Orca/Overview/orca
-            title: "Orca in 5 miniutes"
+            title: "Orca in 5 minutes"
           - file: doc/Orca/Overview/install
             title: "Installation"
           - file: doc/Orca/Overview/index
@@ -39,7 +39,7 @@ subtrees:
                 - file: doc/Orca/Overview/distributed-tuning
                 - file: doc/Orca/Overview/ray
           - file: doc/Orca/QuickStart/index
-            title: "Tutorials"
+            title: "Quick Examples"
             subtrees:
               - entries:
                 - file: doc/UseCase/spark-dataframe
@@ -48,6 +48,11 @@ subtrees:
                 - file: doc/Orca/QuickStart/orca-pytorch-distributed-quickstart
                 - file: doc/Orca/QuickStart/orca-autoestimator-pytorch-quickstart
                 - file: doc/Orca/QuickStart/orca-autoxgboost-quickstart
+          - file: doc/Orca/Tutorial/index
+            title: "Tutorials"
+            subtrees:
+              - entries:
+                - file: doc/Orca/Tutorial/yarn
           - file: doc/Orca/Overview/known_issues
             title: "Tips and Known Issues"
           - file: doc/PythonAPI/Orca/index

docs/readthedocs/source/doc/Orca/Overview/getstarted.rst

@@ -1,2 +0,0 @@
-Orca Key Features
-=================================

docs/readthedocs/source/doc/Orca/Overview/install.md

@@ -1,7 +1,7 @@
 # Installation
 
 
-## To use Distributed Data processing, training, and/or inference
+## To use basic Orca features
 We recommend using [conda](https://docs.conda.io/projects/conda/en/latest/user-guide/install/) to prepare the Python environment.
 ```bash
 conda create -n py37 python=3.7  # "py37" is conda environment name, you can use any name you like.
@@ -14,32 +14,38 @@ You can install bigdl-orca nightly build version using
 pip install --pre --upgrade bigdl-orca
 ```
 
-## To use RayOnSpark
+## To additionally use RayOnSpark
 
-There're some additional dependencies required for running [RayOnSpark](ray.md). Use extra key `[ray]` to install.
+If you wish to run [RayOnSpark](ray.md) or [sklearn-style Estimator APIs in Orca](distributed-training-inference.md) with "ray" backend, use the extra key `[ray]` during the installation above:
 
 ```bash
 pip install bigdl-orca[ray]
 ```
 
-or to install nightly build, use
+or for the nightly build version, use
 ```bash
 pip install --pre --upgrade bigdl-orca[ray]
 ```
 
-## To use Orca AutoML
+Note that with the extra key of [ray], `pip` will automatically install the additional dependencies for RayOnSpark,
+including `ray[default]==1.9.2`, `aiohttp==3.8.1`, `async-timeout==4.0.1`, `aioredis==1.3.1`, `hiredis==2.0.0`, `prometheus-client==0.11.0`, `psutil`,  `setproctitle`.
 
-There're some additional dependencies required for Orca AutoML support. Use extra key `[automl]` to install.
+## To additionally use AutoML
+
+If you wish to run AutoML, use the extra key `[automl]` during the installation above:
 
 ```bash
 pip install bigdl-orca[automl]
 ````
 
+or for the nightly build version, use
+```bash
+pip install --pre --upgrade bigdl-orca[automl]
+```
 
-_Note that with extra key of [automl], `pip` will automatically install the additional dependencies for distributed hyper-parameter tuning,
+Note that with the extra key of [automl], `pip` will automatically install the additional dependencies for distributed hyper-parameter tuning,
-including `ray[tune]==1.9.2`, `scikit-learn`, `tensorboard`, `xgboost`._
+including `ray[tune]==1.9.2`, `scikit-learn`, `tensorboard`, `xgboost` together with the dependencies given by the extra key [ray].
 
-To use [Pytorch Estimator](#pytorch-autoestimator), you need to install Pytorch with `pip install torch==1.8.1`.
+- To use [Pytorch Estimator](#pytorch-autoestimator), you need to install Pytorch with `pip install torch==1.8.1`.
-
-To use [TensorFlow/Keras AutoEstimator](#tensorflow-keras-autoestimator), you need to install Tensorflow with `pip install tensorflow==1.15.0`.
 
+- To use [TensorFlow/Keras AutoEstimator](#tensorflow-keras-autoestimator), you need to install TensorFlow with `pip install tensorflow==1.15.0`.

docs/readthedocs/source/doc/Orca/Overview/orca.md

@@ -6,9 +6,11 @@ Most AI projects start with a Python notebook running on a single laptop; howeve
 
 ---
 
-### Tensorflow Bite-sized Example
+### TensorFlow Bite-sized Example
 
-This section uses TensorFlow 1.15, and you should install TensorFlow before running this example:
+First of all, follow the steps [here](install.md#to-use-basic-orca-features) to install Orca in your environment.
+
+This section uses TensorFlow 1.15, and you should also install TensorFlow before running this example:
 ```bash
 pip install tensorflow==1.15
 ```

docs/readthedocs/source/doc/Orca/Overview/ray.md

@@ -14,7 +14,7 @@ _**Note:** BigDL has been tested on Ray 1.9.2 and you are highly recommended to
 
 We recommend using [conda](https://docs.conda.io/projects/conda/en/latest/user-guide/install/) to prepare the Python environment.
 When installing bigdl-orca with pip, you can specify the extras key `[ray]` to install the additional dependencies
-for running Ray (i.e. `ray==1.9.2`, `psutil`, `aiohttp==3.7.0`, `aioredis==1.1.0`, `setproctitle`, `hiredis==1.1.0`, `async-timeout==3.0.1`):
+for running Ray (i.e. `ray[default]==1.9.2`, `aiohttp==3.8.1`, `async-timeout==4.0.1`, `aioredis==1.3.1`, `hiredis==2.0.0`, `prometheus-client==0.11.0`, `psutil`,  `setproctitle`):
 
 ```bash
 conda create -n py37 python=3.7  # "py37" is conda environment name, you can use any name you like.

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

@@ -1,4 +1,4 @@
-# Orca Tutorial
+# Orca Quickstarts
 
 
 - [**Orca TensorFlow 1.15 Quickstart**](./orca-tf-quickstart.html)

docs/readthedocs/source/doc/Orca/Tutorial/index.rst

@@ -0,0 +1,6 @@
+Orca Tutorials
+=================================
+
+* `Run on Hadoop/YARN clusters <yarn.html>`_
+* `Run on Azure Databricks <../../UserGuide/databricks.html>`_
+* `Run on Google Colab <../../UserGuide/colab.html>`_

docs/readthedocs/source/doc/Orca/Tutorial/yarn.md

@@ -1,4 +1,4 @@
-# Running BigDL-Orca on Hadoop/YARN Clusters
+# Run on Hadoop/YARN Clusters
 
 This tutorial provides a step-by-step guide on how to run BigDL-Orca programs on Apache Hadoop/YARN clusters, using a [PyTorch Fashin-MNIST program](https://github.com/intel-analytics/BigDL/blob/main/python/orca/tutorial/pytorch/FashionMNIST/) as a working example.
 

docs/readthedocs/source/doc/UseCase/spark-dataframe.md

@@ -1,4 +1,4 @@
-# Use Spark Dataframe for Deep Learning
+# Use Spark DataFrames for Deep Learning
 
 ---