Add different approaches for creation of the app.py file for different operating systems.
Add option for Windows.

Improve build-images.md for Windows Users

ctrl-c does not work after running the container in non-detached mode.
Therefore I added a note to stop the container from within Docker Desktop.

Add approach to prevent getting stuck in run-containers.md

I deleted the backslashes in two code sections (which where meant to escape the newline - as far as I know).
It is not possible to write and use the code as described (with the backslashes) - at least in my case of Windows CMD.
With the changes one can now see actually usable code, which one can just copy and paste - even if one does not know that the backslashes must be deleted before.
I don't think the backslashes make it easier to understand these parts.
For deeper understanding however the [volumes page](https://docs.docker.com/storage/volumes/) is already referenced before.

Delete backslashes in code of develop.md