Update download badge to a working one

the provider seems too unstable.

README.md

@@ -111,7 +111,7 @@ asyncio.run(main())
 
 Niquests allows you to send HTTP requests extremely easily. There’s no need to manually add query strings to your URLs, or to form-encode your `PUT` & `POST` data — just use the `json` method!
 
-[![Downloads](https://static.pepy.tech/badge/niquests/month)](https://pepy.tech/project/niquests)
+[![Downloads](https://img.shields.io/pypi/dm/niquests.svg)](https://pypistats.org/packages/niquests)
 [![Supported Versions](https://img.shields.io/pypi/pyversions/niquests.svg)](https://pypi.org/project/niquests)
 
 This project does not require any compilation toolchain. The HTTP/3 support is not enforced and installed if your platform can support it natively _(e.g. pre-built wheel available)_.