Update getting started instructions.
Update getting started instructions.

GoogleCloudPlatform/cloud-bigtable-examples,nlpraveennl/cloud-bigtable-examples,sduskis/cloud-bigtable-examples,sduskis/cloud-bigtable-examples,sduskis/cloud-bigtable-examples,sduskis/cloud-bigtable-examples,GoogleCloudPlatform/cloud-bigtable-examples,nlpraveennl/cloud-bigtable-examples,sduskis/cloud-bigtable-examples,GoogleCloudPlatform/cloud-bigtable-examples,nlpraveennl/cloud-bigtable-examples,sduskis/cloud-bigtable-examples,nlpraveennl/cloud-bigtable-examples,GoogleCloudPlatform/cloud-bigtable-examples,sduskis/cloud-bigtable-examples