Add Terraform Support

[GlennTatum]

Infrastructure should be managed in a declarative manner to ease development and standardize deployment.

The current resources being utilized by Document Processor on Google Cloud Platform are:

• Document AI (https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/document_ai_processor)
• OAuth
• Cloud Storage (https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/storage_bucket)
• Firebase/Firestore (https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/firestore_database)
• Service Account (https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/google_service_account_iam)
• Cloud Run (Deployment)

Terraform can be used as a medium for declaring this infrastructure. Links are provided to the dedicated Terraform resources that can be utilized for deployment.