fix badge (#87)

Co-authored-by: LasNikas <[email protected]>

Author: LasNikas

index.md

@@ -119,7 +119,7 @@ listed above. Author names of Trixi.jl's main developers are in *italics*.
 * *Neher*, *Faulhaber*, *Berger*, Weißenfels, *Gassner*, *Schlottke-Lakemper*
   **Robust and efficient pre-processing techniques for particle-based methods including dynamic boundary generation**, 2025.\\
   [![arXiv:](https://img.shields.io/badge/arXiv-2506.21206-yellow)](https://arxiv.org/abs/2506.21206)
-  [![reproduce me!](https://zenodo.org/badge/DOI/10.5281/zenodo.15730554.svg)](https://doi.org/10.5281/zenodo.15730554)
+  [![reproduce me!](https://img.shields.io/badge/reproduce-me!-brightgreen)](https://doi.org/10.5281/zenodo.15730554)
 
 * Babbar, Churavy, *Schlottke-Lakemper*, *Ranocha*,
   **Automatic differentiation for Lax-Wendroff-type discretizations**, 2025.\\