feat(terraform-docs): Add support for replace mode for TF 0.12+; Use native saving to file for TF 0.12+. Both requires terraform-docs v0.12.0+ which released in 2021.

feat(terraform-docs): Add support for replace mode for TF 0.12+; Use native saving to file for TF 0.12+. Both requires terraform-docs v0.12.0+ which released in 2021. #944