Update README to link to docs

Cleaned up the README file to link to the docs pages. Switched from .rst to .md.

README.md

+# GWDataFind Server
+
+This module defines a Flask Application that serves data URLs based on the contents of a diskcache.
+A link to the documentation page can be found [here](https://computing.docs.ligo.org/gwdatafind/server/index.html).
+
+### Requirements
+
+* Python >= 3.4
+* Flask >= 1.0.0
+
+## Apache + Gunicorn configuration
+
+For a detailed description of how to set up and configure a datafind server, 
+please see [here](https://computing.docs.ligo.org/gwdatafind/server/configuration.html).
+
+## Client API
+
+A detailed explination of the API can be found [here](https://computing.docs.ligo.org/gwdatafind/server/api/v1.html).