New Features
- Add Notebook/NbCell session methods, CellRow snapshots,
summary_nb/find_cells,cell_ast_replace; rename find→find_cellsand view→view_cell(#862) - Add fastcore.editskill module documenting shared editing conventions and re-exporting tools + nbio; switch pyskills entry point to it (#861)
- Add metadata directives as XML attrs in cell2xml (#860)