Documentation of Donor metadata and examples of how to query

[shirey]

Create a page of documentation explaining how Donor Metadata is stored using ontology terms/concepts including a separate page (maybe pages?) of reference for the various ontology pieces that we use from the Donor metadata valuesets spreadsheet for Race, Ethnicity, Age, Sex, Measurements, Cause of Death, Mechanism of Injury, Death Event, Blood Type, Medical History and Social History. (Need to include a Note/Warning that we mainly have Race, Ethnicity, Age and Sex information for Donors and other data is sparse.)

Also, create a Jupyter notebook with some example queries using both the /param-search and search endpoints. Link the Jupyter notebook from this new page of documentation. (Store the Jupyter notebook in GitHub at https://github.com/hubmapconsortium/search-api/tree/main/examples where other Jupyter search examples exist and link directly into GitHub.)