write_pants_xl: Write Excel XLSX file with links to CSVs
In jdreyf/PANTS: Pathway analysis via network smoothing

Create directory; write CSV files with stats from feat.tab for all features in each pathway, and the top features that impact each pathway (even if they're outside the pathway); and write an Excel XLSX file using writexl that links to the CSVs.

1	write_pants_xl(zscores, pwy.tab, feat.tab, Gmat, ker, name, ntop = 5)

`zscores`	Matrix with rownames as feature names, and 1st column with z-scores to select high impact nodes. Non-`NA` values should be finite.
`pwy.tab`	A table of pathway results.
`feat.tab`	Table of feature (e.g. gene) statistics and annotation, with `score` column.
`Gmat`	Binary feature (e.g. gene) by pathway inclusion matrix, indicating which features are in which pathways.
`ker`	Laplacian kernel matrix representing the interaction network.
`name`	Name for the folder and Excel file that get written. Set to `NA` to avoid writing output.
`ntop`	Number of top features that most impact a pathway to include.