add method
Add a data document to this collection and returns a DocumentReference to this document.
If no name
is provided, an auto-generated name is used.
If no data
is provided, this can be set later using the DocumentReference.setData() method.
Implementation
Future<DocumentReference> add([
String? name,
Map<String, dynamic>? data,
]) async {
final newDocument = document(name);
if (data != null) await newDocument.setData(data);
return newDocument;
}