make a vignette per sourmash output type

[x] signatures (output by sourmash sketch or sourmash compute):
- read_signature(), show how to read multiple signatures using purrr,
- upset plots: from_signatures_to_upset_df(), plot_signatures_upset()
- rarefaction plots for signatures sketched from reads: from_signatures_to_rarefaction_df(), plot_signatures_rarefaction()
[x] sourmash compare csv:
- read_compare()
- MDS plot: make_compare_mds(), plot_compare_mds()
- heatmap: plot_compare_heatmap()
[x] sourmash taxonomy annotate csv
- read_taxonomy_annotate()
- taxonomy agglomeration: tax_glom_taxonomy_annotate()
  - upset plot: from_taxonomy_annotate_to_upset_inputs(), plot_taxonomy_annotate_upset()
  - sankey plot: plot_taxonomy_annotate_sankey()
  - time series alluvial plot: plot_taxonomy_annotate_ts_alluvial()
  - to metacoder: from_taxonomy_annotate_to_metacoder()
  - to phyloseq: from_taxonomy_annotate_to_phyloseq()
[x] sourmash gather csv
- read_gather()
- barchart: plot_gather_classified()
- upset plot: from_gather_to_upset_df(), plot_gather_upset()
[x] upset utilities
- from_list_to_upset_df()
- from_upset_df_to_intersection_members()
- from_upset_df_to_intersection_summary()
- from_upset_df_to_intersections()

Arcadia-Science / sourmashconsumr