Small README style updates (#18)

Author: KevinGrandon

README.md

@@ -2,20 +2,26 @@
 
 [![Build status](https://badge.buildkite.com/3f2d84d5538d87a19677f5d79304ac46a8a67f970520d13884.svg?branch=master)](https://buildkite.com/uberopensource/fusion-plugin-react-helmet-async)
 
-Allows adding content into head via a component driven api
+Allows adding content into the document head via a component driven api.
+
+---
 
 ### Table of contents
 
 * [Installation](#installation)
 * [Usage](#usage)
 * [Setup](#setup)
 
+---
+
 ### Installation
 
 ```sh
 yarn add fusion-plugin-react-helmet-async
 ```
 
+---
+
 ### Usage
 
 This plugin is a simple wrapper on the [`react-helmet-async`](https://github.com/NYTimes/react-helmet-async) module which handles
@@ -35,6 +41,8 @@ const app = (
 );
 ```
 
+---
+
 ### Setup
 
 This module has no dependencies or configuration. Simply register the plugin.