docs(firestore): Fix typo in data model reference (#18835)
docs(firestore): Fix typo in data model reference (#18835)


dazuma/google-cloud-ruby,googleapis/google-cloud-ruby,dazuma/google-cloud-ruby,googleapis/google-cloud-ruby,dazuma/google-cloud-ruby,googleapis/google-cloud-ruby,googleapis/google-cloud-ruby,dazuma/google-cloud-ruby,dazuma/google-cloud-ruby,googleapis/google-cloud-ruby,googleapis/google-cloud-ruby,dazuma/google-cloud-ruby