As a user I want to be informed by the README that I need to have Docker installed

[mkrause-nps]

Use-case: I'm in the process of installing RITA. I did this on a fresh Ubuntu VM, where Docker isn't installed. I didn't know that the installer depends on it.

New feature: mention in README that user needs to install Docker before running the installer

[0x6d6f7468]

Hey @mkrause-nps , thanks for opening an issue.

RITA's pre-installation process will automatically install Docker, so users shouldn't have to worry about installing Docker manually.

Can you please try installing the latest release of RITA and let us know if this solves your issue?

Thanks.