Add download badges to ReadMe (#1172)

Added badges to show download volumes on npm, pypi, and docker.

Author: svix-ken

README.md

@@ -14,6 +14,10 @@
 [![Twitter Follow](https://img.shields.io/twitter/follow/SvixHQ?style=social)](https://twitter.com/SvixHQ)
 [![Join our slack](https://img.shields.io/badge/Slack-join%20the%20community-blue?logo=slack&style=social)](https://www.svix.com/slack/)
 
+[![Docker Pulls](https://img.shields.io/docker/pulls/svix/svix-server?logo=docker)](https://hub.docker.com/r/svix/svix-server/)
+[![NPM Downloads](https://img.shields.io/npm/dt/svix?logo=npm)](https://www.npmjs.com/package/svix)
+[![Pypi Downloads](https://img.shields.io/pypi/dm/svix?logo=pypi)](https://pypi.org/project/svix/)
+
 ## Svix is the enterprise ready webhook service
 
 Svix makes it easy for developers to send webhooks. Developers make one API call, and Svix takes care of deliverability, retries, security, and more. For more information, please refer to the [Svix homepage](https://www.svix.com).