JSDoc
Adds a document to the index.
Before adding fields to the index the index should have been fully setup, with the document
ref and all fields to index already having been specified.
The document must have a field name as specified by the ref (by default this is 'id') and
it should have all fields defined for indexing, though null or undefined values will not
cause errors.
Entire documents can be boosted at build time. Applying a boost to a document indicates that
this document should rank higher in search results than other documents.