"Refactor README badge links for cleaner syntax"

Replaced `a` tags with Markdown syntax for badges and links to improve readability and consistency. This change simplifies the structure while maintaining the same functionality and visual appearance.

README.md

 <div align="center">
-<a href="https://scs.pages.ub.uni-bielefeld.de/cocosy/cooperative-cuisine/cooperative_cuisine.html">
-![Docs](https://gitlab.ub.uni-bielefeld.de/scs/cocosy/cooperative-cuisine/badges/main/pipeline.svg?key_text=Docs&key_width=35)
-</a>
+[![Docs](https://gitlab.ub.uni-bielefeld.de/scs/cocosy/cooperative-cuisine/badges/main/pipeline.svg?key_text=Docs&key_width=35)](https://scs.pages.ub.uni-bielefeld.de/cocosy/cooperative-cuisine/cooperative_cuisine.html)
 </div>
 <div align="center">
-<a href="https://gitlab.ub.uni-bielefeld.de/scs/cocosy/cooperative-cuisine/-/pipelines/latest/">
-![Main Pipeline Report](https://gitlab.ub.uni-bielefeld.de/scs/cocosy/cooperative-cuisine/badges/main/pipeline.svg?key_text=Main+Pipeline&key_width=82)
-</a>
-<a href="https://gitlab.ub.uni-bielefeld.de/scs/cocosy/cooperative-cuisine/-/pipelines/latest/">
-![Main Coverage Report](https://gitlab.ub.uni-bielefeld.de/scs/cocosy/cooperative-cuisine/badges/main/coverage.svg?job=pytest&key_text=Main+Test+Coverage&key_width=114)
-</a>
+[![Main Pipeline Report](https://gitlab.ub.uni-bielefeld.de/scs/cocosy/cooperative-cuisine/badges/main/pipeline.svg?key_text=Main+Pipeline&key_width=82)](https://gitlab.ub.uni-bielefeld.de/scs/cocosy/cooperative-cuisine/-/pipelines/latest/)
+[![Main Coverage Report](https://gitlab.ub.uni-bielefeld.de/scs/cocosy/cooperative-cuisine/badges/main/coverage.svg?job=pytest&key_text=Main+Test+Coverage&key_width=114)](https://gitlab.ub.uni-bielefeld.de/scs/cocosy/cooperative-cuisine/-/pipelines/latest/)
 ![Dev Pipeline Report](https://gitlab.ub.uni-bielefeld.de/scs/cocosy/cooperative-cuisine/badges/dev/pipeline.svg?key_text=Dev+Pipeline&key_width=80)
 ![Dev Coverage Report](https://gitlab.ub.uni-bielefeld.de/scs/cocosy/cooperative-cuisine/badges/dev/coverage.svg?job=pytest&key_text=Dev+Test+Coverage&key_width=112)
 </div>