chore: update docs title for bigquery reservation (#3295)
chore: update docs title for bigquery reservation (#3295)


googleapis/google-cloud-php,jdpedrie/google-cloud-php,googleapis/google-cloud-php,jdpedrie/google-cloud-php,googleapis/google-cloud-php,chingor13/google-cloud-php,jdpedrie/google-cloud-php,chingor13/google-cloud-php,chingor13/google-cloud-php