[docs] Restructure README.md content (tensorflow#1257)

* Refactor README.md content

* bump to run ci jobs

.github/workflows/build.yml

@@ -55,7 +55,7 @@ jobs:
           echo $PATH
           python3 --version
           python3 -c 'import site; print(site.getsitepackages())'
-          python3 .github/workflows/build.instruction.py --sudo=true README.md "#### macOS" > source.sh
+          python3 .github/workflows/build.instruction.py --sudo=true docs/development.md "#### macOS" > source.sh
           bash -x -e source.sh
           python3 -c 'import tensorflow as tf; print(tf.version.VERSION)'
 
@@ -67,7 +67,7 @@ jobs:
       - run: |
           set -x -e
           bash -x -e .github/workflows/build.space.sh
-          python3 .github/workflows/build.instruction.py README.md "##### Ubuntu 20.04" > source.sh
+          python3 .github/workflows/build.instruction.py docs/development.md "##### Ubuntu 20.04" > source.sh
           cat source.sh
           docker run -i --rm -v $PWD:/v -w /v --net=host ubuntu:20.04 \
             bash -x -e source.sh
@@ -80,7 +80,7 @@ jobs:
       - run: |
           set -x -e
           bash -x -e .github/workflows/build.space.sh
-          python3 .github/workflows/build.instruction.py README.md "##### CentOS 7" > source.sh
+          python3 .github/workflows/build.instruction.py docs/development.md "##### CentOS 7" > source.sh
           cat source.sh
           docker run -i --rm -v $PWD:/v -w /v --net=host centos:7 \
             bash -x -e source.sh

CONTRIBUTING.md

@@ -1,7 +1,6 @@
 # Contributing
 
-Tensorflow I/O project welcomes all kinds of contributions, be it code changes, bug-fixes or documentation changes.
-This guide should help you in taking care of some basic setups & code conventions.
+Tensorflow I/O project welcomes all kinds of contributions, be it code changes, bug-fixes or documentation changes. This guide should help you in taking care of some basic setups & code conventions.
 
 ## Contributor License Agreement
 
@@ -17,8 +16,7 @@ again.
 
 ## Coding Style
 
-Tensorflow project wide code style guidelines can be followed at [TensorFlow Style Guide - Conventions](https://www.tensorflow.org/community/contribute/code_style) and Tensorflow I/O project specific 
-code style guidelines can be followed at [Style Guide](STYLE_GUIDE.md).
+Tensorflow project wide code style guidelines can be followed at [TensorFlow Style Guide - Conventions](https://www.tensorflow.org/community/contribute/code_style) and Tensorflow I/O project specific code style guidelines can be followed at [Style Guide](STYLE_GUIDE.md).
 
 ## Code Reviews