Update readme

README.md

@@ -1,5 +1,10 @@
 Yamale (ya·ma·lē)
 =================
+[![Build Status](https://github.com/23andMe/Yamale/actions/workflows/run-tests.yml/badge.svg)](https://github.com/23andMe/Yamale/actions/workflows/run-tests.yml)
+[![PyPI](https://img.shields.io/pypi/v/yamale.svg)](https://pypi.python.org/pypi/yamale)
+[![downloads](https://static.pepy.tech/badge/yamale/month)](https://pepy.tech/project/yamale)
+[![versions](https://img.shields.io/pypi/pyversions/yamale.svg)](https://github.com/yamale/yamale)
+[![license](https://img.shields.io/github/license/23andMe/yamale.svg)](https://github.com/23andMe/Yamale/blob/master/LICENSE)
 
 | :warning: Ensure that your schema definitions come from internal or trusted sources. Yamale does not protect against intentionally malicious schemas. |
 |:------------|
@@ -11,8 +16,6 @@ A schema and validator for YAML.
 What's YAML? See the current spec [here](http://www.yaml.org/spec/1.2/spec.html) and an introduction
 to the syntax [here](https://github.com/Animosity/CraftIRC/wiki/Complete-idiot's-introduction-to-yaml).
 
-[![Build Status](https://github.com/23andMe/Yamale/actions/workflows/run-tests.yml/badge.svg)](https://github.com/23andMe/Yamale/actions/workflows/run-tests.yml)
-[![PyPI](https://img.shields.io/pypi/v/yamale.svg)](https://pypi.python.org/pypi/yamale)
 
 Requirements
 ------------
@@ -25,6 +28,8 @@ Install
 ### pip
 ```bash
 $ pip install yamale
+# or to include ruamel.yaml as a dependency
+$ pip install yamale[ruamel]
 ```
 
 NOTE: Some platforms, e.g., Mac OS, may ship with only Python 2 and may not have pip installed.