Fix broken link

Author: ufechner7

docs/src/index.md

@@ -130,7 +130,7 @@ If you use this project in your research, please consider citing it.
 Citation details can be found in the [CITATION.cff](https://github.com/Albatross-Kite-Transport/VortexStepMethod.jl/blob/main/CITATION.cff) file included in this repository.
 
 ## License
-This project is licensed under the MIT License - see the [LICENSE]((https://github.com/Albatross-Kite-Transport/VortexStepMethod.jl/blob/main/LICENSE) file for details.
+This project is licensed under the MIT License - see the [LICENSE](https://github.com/Albatross-Kite-Transport/VortexStepMethod.jl/blob/main/LICENSE) file for details.
 
 ## WAIVER
 Technische Universiteit Delft hereby disclaims all copyright interest in the package “VortexStepMethod.jl” written by the Author(s).