Add dashboard GIF and blurb to README

Author: ruohola

README.md

@@ -8,6 +8,10 @@
 [![python versions](https://img.shields.io/pypi/pyversions/apilytics)](#what-python-versions-does-the-package-work-with)
 [![license](https://img.shields.io/pypi/l/apilytics.svg)](https://github.com/apilytics/apilytics-python/blob/master/LICENSE)
 
+Apilytics is a service that lets you analyze operational, performance and security metrics from your APIs without infrastructure-level logging.
+
+<img src="https://www.apilytics.io/mock-ups/time-frame.gif" alt="Apilytics dashboard animation" width="600" height="300" />
+
 ## Installation
 
 1. Sign up and get your API key from https://apilytics.io - we offer a completely free trial with no credit card required!