chore: Add V4 migration guide (#56)
chore: Add V4 migration guide (#56)

* add migration guide

* use list

* Update docs/upgrading_to_bigquery_v4.0.md

Co-Authored-By: Morgante Pell <dc24fe79b12509b3ecaa16577179576288deda72@morgante.net>

* simplify access migration

Co-authored-by: Morgante Pell <dc24fe79b12509b3ecaa16577179576288deda72@morgante.net>

terraform-google-modules/terraform-google-bigquery,terraform-google-modules/terraform-google-bigquery