Provide notebook or script to parse exported JSON into a tree object for downstream analysis

[sidneymbell]

E.g., I'm currently writing a couple of functions to take the auspice tree JSON and import it into a notebook as an ETE toolkit Tree object. If this seems helpful to others, happy to PR this to live alongside the docs. Maintenance will be a bit of work if we change the exported format, but this work is currently being done by a lot of people in tandem / might be worth maintaining in one place for everyone to ease ecosystem integration a bit. LMK what you'd prefer.