[Doc] Migrate requirements file for ReadtheDocs documentation building (#6602)

* Refactor readthedocs yml file to wget requirements-doc.txt for safety purposes

* Remove requirements-doc.txt from BigDL repo

* temp readme

* Remove requirements-rtd.txt and update README for local doc build

* Small typo fix

.readthedocs.yml

@@ -5,9 +5,19 @@
 # Required
 version: 2
 
+build:
+  os: ubuntu-20.04
+  tools:
+    python: "3.7"
+  apt_packages:
+    - graphviz
+  jobs:
+    pre_install:
+      - wget https://raw.githubusercontent.com/analytics-zoo/BigDL/main/python/test/python-requirements/requirements-doc.txt
+
 sphinx:
   configuration: docs/readthedocs/source/conf.py
 
 python:
   install:
-    - requirements: docs/readthedocs/requirements-doc.txt
+    - requirements: ./requirements-doc.txt

docs/readthedocs/README.md

@@ -12,11 +12,16 @@ conda activate docs
 Then inside [`BigDL/docs/readthedocs`](.) folder, install required packages:
 
 ```bash
-pip install --upgrade -r requirements-rtd.txt
+cd docs/readthedocs
+# for reproducing ReadtheDocs deployment environment
+pip install --upgrade pip "setuptools<58.3.0"
+pip install --upgrade pillow mock==1.0.1 "alabaster>=0.7,<0.8,!=0.7.5" commonmark==0.9.1 recommonmark==0.5.0 sphinx sphinx-rtd-theme "readthedocs-sphinx-ext<2.3"
+
+# for other documentation related dependencies
+wget https://raw.githubusercontent.com/analytics-zoo/BigDL/main/python/test/python-requirements/requirements-doc.txt
 pip install -r requirements-doc.txt
 ```
-> **Note**: `requirements-rtd.txt` is for reproducing ReadtheDocs deployment environment. No need to modify this file when adding new sphinx extension for our documentation. New packages should be added in `requirements-doc.txt`.
-
+> **Note**: When adding new sphinx extensions for our documentation, the requirements file located [here](https://github.com/analytics-zoo/BigDL/blob/main/python/test/python-requirements/requirements-doc.txt) should be modified.
 ### 2. Build the documentation
 You can then build the documentation locally through:
 ```bash

docs/readthedocs/requirements-doc.txt

@@ -1,44 +0,0 @@
-sphinx-copybutton==0.5.0
-sphinx-version-warning==1.1.2
-sphinx-click==4.3.0
-sphinx-jsonschema==1.19.1
-sphinxemoji==0.2.0
-click==8.1.3
-markdown<3.4
-tensorflow==1.15.2
-bigdl==0.12.0
-cloudpickle==2.1.0
-ray[tune]==1.9.2
-ray==1.9.2
-torch==1.11.0
-Pygments==2.7
-setuptools==41.0.1
-docutils==0.17.1
-mock==1.0.1
-pillow==5.4.1
-sphinx==4.5.0
-alabaster>=0.7,<0.8,!=0.7.5
-commonmark==0.8.1
-recommonmark==0.5.0
-readthedocs-sphinx-ext<2.2
-scikit-learn==1.0.2
-pystan==2.19.1.1
-prophet==1.0.1
-pmdarima==1.8.5
-sphinx_markdown_tables==0.0.15
-numpy==1.21.2
-xgboost==1.6.1
-torchmetrics==0.7.2
-pickle5==0.0.12
-protobuf~=3.19.0
-sphinx-tabs==3.4
-optuna==2.10.0
-ConfigSpace==0.5.0
-sphinx-design==0.2.0
-sphinx-external-toc==0.3.0
-nbsphinx==0.8.9
-ipython==7.34.0
-sphinx-design==0.2.0
-nbsphinx-link==1.3.0
-pydata-sphinx-theme==0.11.0
-sphinxcontrib-mermaid==0.7.1

docs/readthedocs/requirements-rtd.txt

@@ -1,9 +0,0 @@
-setuptools<58.3.0
-pillow
-mock==1.0.1
-alabaster>=0.7,<0.8,!=0.7.5
-commonmark==0.9.1
-recommonmark==0.5.0
-sphinx
-sphinx-rtd-theme
-readthedocs-sphinx-ext<2.2