[Feature Request[ Allow multiple template Jupyter notebooks

The multi-run Hatchet notebooks are fantastic, and they're going to be hugely popular for our use cases. But I find myself writing the same changes to that notebook several times (filter out the non-Kokkos results from dataframes, make the "reference" performance results come from "reference.cali").

Short term I'll of course just change the notebook that gets generated for Kokkos-specific installs of this thing, but it would be neat if we gave users the ability to add new notebook templates. That said, the notebook is probably my favorite tool for quickly telling me I don't need to care about my performance results that morning.

Start by examining the generated multi-run Hatchet notebook and how notebooks are produced for Kokkos-specific installs. Determine where notebook templates are selected and define how users would add and select new templates; done means users can generate a customized template without repeatedly editing the generated notebook.

Written by the indexing model from the issue text.