IPython cell magic for enabling Treescope in a single cell

I'd like to get the treescope visualizations in notebooks only if I decorate a cell with `%%autovisualize`. However, `%%autovisualize` doesn't seem to have any effect. I can only use treescope everywhere (with `basic_interactive_setup()`) or nowhere.

I am aware of `treescope.show`, but I'd still like to use `%%autovisualize` because it is nicely separated from the code content of the cell.

Thank you for sharing this great library!