Set `frictionlessdata` as default keyword

[peterdesmet]

trafficstars

To better identify Frictionless Data Packages on Zenodo, CKAN, etc. it was suggested on slack to add the keyword frictionlessdata to such deposits (frictionless being too generic). To facilitate this use, it would be nice if write_to_zenodo() added this keyword by default.

[shashigharti]

Thanks for the request!