Updates needed to Diffbind Rmd reports

[tovahmarkowitz]

1. Add library size information
2. Add differential peak counts table
3. Recolor peak heatmaps: pick a more variable color scale from hcl.colors() like PuBuGn or Batlow
   https://journal.r-project.org/articles/RJ-2023-071/

[tovahmarkowitz]

to get library size: pv$class