[NTH] Ensure that CMakeLists.txt is following the best practices

Since this project is partially aimed at developers improving their C++ and CMake skills I create this issue. The issue should be constantly ongoing and if we realize that some of our practices in CMakeLists.txt are not ideal we should make a PR referencing it.

This is a nice source to learn about the modern best practices for CMake: https://cliutils.gitlab.io/modern-cmake/

- **Difficulty (1-10):**
2

- **Location/Files:**
`CMakeLists.txt`

Start by reading the repository's CMakeLists.txt and compare its practices with the linked Modern CMake guide. The issue does not identify a specific improvement or define completion, so a contributor would need to select and scope one concrete CMake change before work can be considered done.

Written by the indexing model from the issue text.