preprint

DEV: Initial commit of demo (#1)

* DEV: Initial commit of demo

* DEV: Use `piqtree[extra]` for jupyter

* DEV: New type env var no longer required

* DEV: Use PyPI version of piqtree

* DEV: Update lock file

* MAINT: No longer use `new_type`

* MAINT: Add progress bar to non-app demo