add OpenSSF best practices badge (#1885)

* add OpenSSF best practices badge

* remove broken Genie badge

README.md

@@ -10,7 +10,8 @@
 [![Aqua QA](https://raw.githubusercontent.com/JuliaTesting/Aqua.jl/master/badge.svg)](https://github.com/JuliaTesting/Aqua.jl)
 [![License: MIT](https://img.shields.io/badge/License-MIT-success.svg)](https://opensource.org/licenses/MIT)
 [![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.3996439.svg)](https://doi.org/10.5281/zenodo.3996439)
-[![Downloads](https://shields.io/endpoint?url=https://pkgs.genieframework.com/api/v1/badge/Trixi)](https://pkgs.genieframework.com?packages=Trixi)
+[![OpenSSF Best Practices](https://www.bestpractices.dev/projects/8695/badge)](https://www.bestpractices.dev/projects/8695)
+<!-- [![Downloads](https://shields.io/endpoint?url=https://pkgs.genieframework.com/api/v1/badge/Trixi)](https://pkgs.genieframework.com?packages=Trixi) -->
 <!-- [![GitHub commits since tagged version](https://img.shields.io/github/commits-since/trixi-framework/Trixi.jl/v0.3.43.svg?style=social&logo=github)](https://github.com/trixi-framework/Trixi.jl) -->
 <!-- [![PkgEval](https://juliaci.github.io/NanosoldierReports/pkgeval_badges/T/Trixi.svg)](https://juliaci.github.io/NanosoldierReports/pkgeval_badges/report.html) -->