Classify ChIP/ATAC-Seq peaks based on features provided in a GFF

Peaks are provided in a BED file sorted by chromosome and position. The GFF
must be sorted by chromosome and position, with gene-level features separated
by ### tags and each gene organized into subfeatures such as transcripts and
exons.  This is the default for common data sources.

WWW: https://github.com/auerlab/peak-classifier
