STY: Update readme

README.md

@@ -1,7 +1,6 @@
 # pysatCDF
 [![PyPI Package latest release](https://img.shields.io/pypi/v/pysatcdf.svg)](https://pypi.python.org/pypi/pysatcdf)
 [![Build Status](https://github.com/pysat/pysatCDF/actions/workflows/main.yml/badge.svg)](https://github.com/pysat/pysatCDF/actions/workflows/main.yml/badge.svg)
-[![Documentation Status](https://readthedocs.org/projects/pysatcdf/badge/?version=latest)](http://pysatcdf.readthedocs.io/en/latest/?badge=latest)
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 [![DOI](https://zenodo.org/badge/51764432.svg)](https://zenodo.org/badge/latestdoi/51764432)
 
@@ -33,10 +32,12 @@ with pysatCDF.CDF(filename) as cdf:
 ```
 
 # Testing
-pysatCDF has been tested on Mac OS X and Ubuntu 15.04. Support is included for building on windows if the mingw environment is present. 
+pysatCDF has been tested on Mac OS X and Ubuntu 15.04. Support is included 
+for building on windows via Windows Subsystem for Linux. 
 
 # Motivation
-Provide simple, robust access to CDF data in Python and simplify adding instruments to [pysat](https://github.com/rstoneback/pysat).
+Provide simple, robust access to CDF data in Python and simplify 
+adding instruments to [pysat](https://github.com/pysat/pysat).
 
 # Installation in POSIX compatible environments
 Actual CDF loading is performed by the [NASA CDF libraries] (http://cdf.gsfc.nasa.gov/html/sw_and_docs.html) 
@@ -49,6 +50,16 @@ cd pysatCDF
 python setup.py install
 ```
 
+# Installing pysatCDF in MacOS
+
+MacOS does not ship with a Fortran compiler. One method for getting a suitable
+build environment is to use brew.
+```
+brew install gcc
+```
+
+and then install pysatCDF as normal.
+
 # Installing pysatCDF in Windows
 
 Install the Windows Subsytem for Linux and proceed as per POSIX installation.