Update retrieve.go
add comment createDocReferenceFromString
@@ -41,6 +41,7 @@ func createCollectionReference(client *firestore.Client) {
func createDocReferenceFromString(client *firestore.Client) {
// [START firestore_data_reference_document_path]
+ // Reference to a document with id "alovelace" in the collection "users"
alovelaceRef := client.Doc("users/alovelace")
// [END firestore_data_reference_document_path]
