Update the docs to reflect the Golang version requirement.
Update the docs to reflect the Golang version requirement.

PiperOrigin-RevId: 315688387
Change-Id: Ic998cb4e8f5e01c3dc3bce2c1a21e0d9ee4227b1

GoogleCloudPlatform/healthcare-data-harmonization,GoogleCloudPlatform/healthcare-data-harmonization,GoogleCloudPlatform/healthcare-data-harmonization,GoogleCloudPlatform/healthcare-data-harmonization,GoogleCloudPlatform/healthcare-data-harmonization,GoogleCloudPlatform/healthcare-data-harmonization