Merge branch 'rnou/directory_support' into 'main'

Directory support

This MR adds two features:

- Creation of directories on the output. As cargo is normally running in the prolog the user has zero capabilities to create directories on the adhoc filesystem (as it is ephemeral). This MR creates the needed directories.

- If the input contains a directory, we get all the files recursively. Before this MR only files can be used as input. The behaviour is that the input is used as prefix, i.e., relative directory, and will be put inside the output.

- Prepares for 0.3.0 release 

 The Merge request goes over !16

See merge request !18