Create data directory dynamically

[PorkShoulderHolder]

As discussed, create the data directory as needed in the directory where the cli is being installed/used

1. only create it when it is required and an existing one does not exist.
2. Depending on how often the user is manipulating the contents directly, consider making it a .dot directory so it is invisible and doesn't clutter the user's file system (like the similar .git directory)
3. print out what is going on as it happens, (optionally using input() to confirm). The user needs to know that this folder is being created when it happens, and exactly where they can find it.

[miriamkw]

Tasks:

• Refactor to get all files in data-folder instead of having a separate results-folder
• Update CLI to implement these changes
• Implement changes to install.sh
• Decide: should any folders be hidden? If yes, add changes til install.sh and setup.py
• Add print statements with details about what is happening
• Update README to desribe CLI with pypi instead of the whole code repo