Example button for demo

[sverhoeven]

To give demos it would be nice to have the ability to load an example from one of the scenario pages. Refine it in the workflow builder, show the resulting caprieval result, browse the module output and possibly re-run a module like rescore.
To prepare for the demo you would have the example already completed before you give the demo.

Describe alternatives you've considered
Manually doing tutorial like https://www.bonvinlab.org/education/HADDOCK3/HADDOCK3-protein-glycan/ , but reconstructing the workflow in the builder from scratch would take too long and high chance of mistakes.

[sverhoeven]

In #155 working on demo where you need to copy files and residues list from a Markdown file.