The implementation of the footprints viewer in DM-15823 uses a VOTableFile to include the variable-length spans and peaks. The table is serialized as tabledata format. Prototyping has shown that that the table can be made 3 times smaller by outputting as binary2 format. This ticket is to implement binary2 format in a manner that works with Firefly's current libraries and that also passes STILTS votlint.

Some Markdown items in the example notebook will also be improved.