Add onboarding library (new functionalities tour)

[MartaOB]

First check the possibilities of adding this new tool and test if it works/fits in the dashboard. If the outcome is positive, proceed to implementation.

[MartaOB]

The Intro.js library has been tested and integrated into the dashboard. This feature will be deployed when a new functionality requiring a tutorial is implemented or if we decide to add a tutorial to an existing one.