Add requirements.txt for convenient dependency installation

[Luro02]

https://stackoverflow.com/a/60039420

[I-Al-Istannen]

This project uses setuptools which includes all dependencies, but I guess I can also provide a requirements.txt. Closed by 9cbea5f.

[Luro02]

This project uses setuptools which includes all dependencies

how would this be used to install the required dependencies?

[I-Al-Istannen]

pip will install them automatically when you install the PFERD module. I added a requirements.txt though in the commit mentioned above.