Add documentation to visualize results with ChimeraX

[luque82]

Referees reported issues visualizing the results with NGL Viewer in the Colab notebook and seem to have disregarded the option using ChimeraX. In the revised version, the ChimeraX option should be ofter as the preferred one and reduce the barrier to help users follow this route. Here are some suggestions:

• Review and revise the description for visualization used in the Quick-Start Guide.
• Write an online tutorial to help users navigate an example.
• Generate an issue to record the tutorial and include the link in the Quick-Start Guide and the online tutorial.