docs: match npm downloads badge style to existing badges

Author: Microck

README.md

@@ -9,7 +9,7 @@
 
 <p align="center">
   <a href="https://github.com/Microck/kagi-cli/releases"><img src="https://img.shields.io/github/v/release/Microck/kagi-cli?display_name=tag&style=flat-square&label=release&color=000000" alt="release badge"></a>
-  <a href="https://www.npmjs.com/package/kagi-cli"><img src="https://badgen.net/npm/dt/kagi-cli" alt="npm downloads"></a>
+  <a href="https://www.npmjs.com/package/kagi-cli"><img src="https://img.shields.io/npm/dt/kagi-cli?style=flat-square&label=downloads&color=000000" alt="npm downloads"></a>
   <a href="https://github.com/Microck/kagi-cli/actions/workflows/ci.yml"><img src="https://img.shields.io/github/actions/workflow/status/Microck/kagi-cli/ci.yml?branch=main&style=flat-square&label=ci&color=000000" alt="ci badge"></a>
   <a href="LICENSE"><img src="https://img.shields.io/badge/license-mit-000000?style=flat-square" alt="license badge"></a>
 </p>