Update docs/usage.md
Update docs/usage.md

Co-Authored-By: apeltzer <23add7f5d474127cfbd07ba5d9a61643ebdd51c4@users.noreply.github.com>
ewels/NGI-RNAseq,ewels/NGI-RNAseq,ewels/NGI-RNAseq,ewels/NGI-RNAseq,ewels/NGI-RNAseq