Better example for the interactive plots

Currently we are using iris to plot in essential libraries (#16). It would be good to use a dataset that shows off interactivity better. One good example is the asteroid dataset from Jake VanderPlas's JHEPC 2013 entry:

https://jhepc.github.io/2013/entry3/index.html

This would enable us to link points between the two plots, a great use of interactivity.

Locate the current iris example in the guide and review the linked asteroid dataset example from Jake VanderPlas's JHEPC 2013 entry. Replace the example with a dataset that demonstrates interactivity and supports linking points between the two plots; done means the guide uses the improved interactive example.

Written by the indexing model from the issue text.