Add PyPI versions supported (#2431)

Author: Kludex

README.md

@@ -4,17 +4,13 @@
 <p align="center">
     <em>✨ The little ASGI framework that shines. ✨</em>
 </p>
-<p align="center">
-<a href="https://github.com/encode/starlette/actions">
-    <img src="https://github.com/encode/starlette/workflows/Test%20Suite/badge.svg" alt="Build Status">
-</a>
-<a href="https://pypi.org/project/starlette/">
-    <img src="https://badge.fury.io/py/starlette.svg" alt="Package version">
-</a>
-</p>
 
 ---
 
+[![Build Status](https://github.com/encode/starlette/workflows/Test%20Suite/badge.svg)](https://github.com/encode/starlette/actions)
+[![Package version](https://badge.fury.io/py/starlette.svg)](https://pypi.python.org/pypi/starlette)
+[![Supported Python Version](https://img.shields.io/pypi/pyversions/starlette.svg?color=%2334D058)](https://pypi.org/project/starlette)
+
 **Documentation**: [https://www.starlette.io/](https://www.starlette.io/)
 
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