Merge pull request #446 from SimonFrings/installations

Add badge to show number of project installations

Author: clue

README.md

@@ -1,6 +1,7 @@
 # HTTP
 
 [![CI status](https://github.com/reactphp/http/workflows/CI/badge.svg)](https://github.com/reactphp/http/actions)
+[![installs on Packagist](https://img.shields.io/packagist/dt/react/http?color=blue&label=installs%20on%20Packagist)](https://packagist.org/packages/react/http)
 
 Event-driven, streaming HTTP client and server implementation for [ReactPHP](https://reactphp.org/).