Consider adding ortholog mappings from Zoonomia

[bschilder]

https://zoonomiaproject.org/the-data/

TOGA annotation of orthologous genes
Annotation of genes across the 240 Zoonomia species —plus many more — inferred using TOGA (Tool to infer Orthologs from Genome Alignments). Files are available as gtf and bed12, with options to reference on human, mouse, chicken, and several other species.