Extend How-to-use in Readme

[FG-TUM]

Description

Readme needs more information on how to use this project in a simple way:

• [ ] example of a fully functional main()
• [ ] CMake integration

Alternatives

The proper way would be to be able to do:

find_package(nasa_breakup)

For starters it might suffice to show the LADDS way of using fetch_content