message: Remove CRAN badge and prefer installation via GitHub
diff: [![GitHub CI](https://github.com/tensorflow/io/workflows/GitHub%20CI/badge.svg?branch=master)](https://github.com/tensorflow/io/actions?query=branch%3Amaster)
  [![PyPI](https://badge.fury.io/py/tensorflow-io.svg)](https://pypi.org/project/tensorflow-io/)
  -[![CRAN](https://www.r-pkg.org/badges/version/tfio)](https://cran.r-project.org/package=tfio)
  [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://github.com/tensorflow/io/blob/master/LICENSE)
  [![Documentation](https://img.shields.io/badge/api-reference-blue.svg)](https://www.tensorflow.org/io)
  @@ -73,13 +72,7 @@ $ pip install tensorflow-io-nightly
  ### R Package
  Once the `tensorflow-io` Python package has been successfully installed, you
  -can then install the latest stable release of the R package via:
  -
  -```r
  -install.packages('tfio')
  -```
  -
  -You can also install the development version from Github via:
  +can install the development version of the R package from GitHub via the following:
  ```r
  if (!require("remotes")) install.packages("remotes")
  remotes::install_github("tensorflow/io", subdir = "R-package")
  