incorporate support for multi-format resources

[ ] Review edits in Eli’s PR
[ ] Create new branch (staging or multi-format-resource-support) and modify Eli’s PR #8 to merge into that branch
[ ] Merge PR into new branch
[ ] Open PR from new branch into main
[ ] Run existing test suite on the updated code to see if anything fails (or we need to modify tests)
[ ] Add internal instructions for how to use sedtR with the staging api (modify zzz.R and sedt_url() fxn)
[ ] Add additional tests of functionality if needed beyond tests/testthat/test-prep_sedt_resource.R

UrbanInstitute / sedtR