Added flattened terms for detecting gene features and transcript features.
Added ApolloGFF3 feature store, which inherits from standard JBrowse GFF3 feature store but adds custom handling of three-level gene-transcript-exon feature hierarchies, in order to be able to properly display transcript-exon in HTMLFeatures and DraggableHTMLFeatures
Registering a file driver that uses ApolloGFF3 store to ensure gene-transcript-exon hierarchies loaded from GFF3 files can be better visualized in HTMLFeatures and DraggableHTMLFeatures
Transforming "Alignments" and "Alignments2" tracks to "DraggableAlignments" by default.