Make README prettier and condense ToC

 People who land on the github page may not spend much time reading and
 may not scroll beyond the fold. Centering the image, title H1, badges
 and ToC will help expose important content, while making the page look
 better, IMO.

Author: zbeekman

README.md

@@ -3,7 +3,7 @@
 [This document is formatted with GitHub-Flavored Markdown.              ]:#
 [For better viewing, including hyperlinks, read it online at            ]:#
 [https://github.com/sourceryinstitute/OpenCoarrays/blob/master/README.md]:#
-
+<div align="center">
 
 [![Sourcery Institute][sourcery-institute logo]](https://www.sourceryinstitute.org)
 
@@ -19,17 +19,19 @@ OpenCoarrays
 [![Twitter URL](https://img.shields.io/twitter/url/http/shields.io.svg?style=social)](https://twitter.com/intent/tweet?hashtags=HPC,Fortran,PGAS&related=zbeekman,gnutools,HPCwire,HPC_Guru,hpcprogrammer,SciNetHPC,DegenerateConic,jeffdotscience,travisci&text=Stop%20programming%20w%2F%20the%20%23MPI%20docs%20in%20your%20lap%2C%20try%20Coarray%20Fortran%20w%2F%20OpenCoarrays%20%26%20GFortran!&url=https%3A//github.com/sourceryinstitute/OpenCoarrays)
 <!-- [![Release Downloads][download img]](https://github.com/sourceryinstitute/OpenCoarrays/releases) -->
 
-* [Overview](#overview)
-* [Downloads](#downloads)
-* [Compatibility](#compatibility)
-* [Prerequisites](#prerequisites)
-* [Installation](#installation)
-* [Getting Started](#getting-started)
-* [Contributing](#contributing)
-* [Status](#status)
-* [Support](#support)
-* [Acknowledgements](#acknowledgements)
-* [Donate](#donate)
+[Overview](#overview) &middot;
+[Downloads](#downloads) &middot;
+[Compatibility](#compatibility) &middot;
+[Prerequisites](#prerequisites) &middot;
+[Installation](#installation) &middot;
+[Getting Started](#getting-started) &middot;
+[Contributing](#contributing) &middot;
+[Status](#status) &middot;
+[Support](#support) &middot;
+[Acknowledgements](#acknowledgements) &middot;
+[Donate](#donate)
+
+</div>
 
 Overview
 --------
@@ -76,7 +78,7 @@ Status
 ------
 
 A list of open issues can be viewed on the
-[issues page](https://github.com/sourcery institute/opencoarrays/issues).
+[issues page](https://github.com/sourceryinstitute/opencoarrays/issues).
 
 Support
 -------