chore(.github): add release please config for root module (#2716)
chore(.github): add release please config for root module (#2716)

Once merged, we can merge the connected PR and then we should
start to see proposed releases for the root module. More work will
need to be done to figure out supporting the sub-modules.

Related: googleapis/release-please#514
googleapis/google-cloud-go,googleapis/google-cloud-go,googleapis/google-cloud-go,googleapis/google-cloud-go