Merge pull request #5 from gnumoksha/patch-1

docs: Standardize the README

Author: shadowhand

README.md

@@ -1,6 +1,12 @@
-HTTP Server Handler
-===================
+HTTP Server Request Handlers for Middleware
+===========================================
 
-Provides the `RequestHandlerInterface` of [PSR-15][psr-15].
+This repository holds the `RequestHandlerInterface` related to [PSR-15 (HTTP Server Request Handlers)][psr-url].
 
-[psr-15]: https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-15-request-handlers.md
+Note that this is not a Server Request Handler implementation of its own. It is merely the interface that describe a Server Request Handler.
+
+The installable [package][package-url] and [implementations][implementation-url] are listed on Packagist.
+
+[psr-url]: https://www.php-fig.org/psr/psr-15/
+[package-url]: https://packagist.org/packages/psr/http-server-handler
+[implementation-url]: https://packagist.org/providers/psr/http-server-handler-implementation