COD-3854 - Add terraform documentation

[richardantal]

No description provided.

[github-actions]

Go test coverage: 32.8% for commit ec0b919

⚠️ 1 of 10 packages have zero coverage.

• github.com/cloudera/terraform-provider-cdp/resources/ml

View coverage for all packages

# Package Name                                                      | Coverage
+ github.com/cloudera/terraform-provider-cdp/cdpacctest             |    30.8%
+ github.com/cloudera/terraform-provider-cdp/provider               |    78.7%
+ github.com/cloudera/terraform-provider-cdp/resources/datahub      |    37.4%
+ github.com/cloudera/terraform-provider-cdp/resources/datalake     |     7.8%
+ github.com/cloudera/terraform-provider-cdp/resources/environments |    47.9%
+ github.com/cloudera/terraform-provider-cdp/resources/iam          |     2.0%
- github.com/cloudera/terraform-provider-cdp/resources/ml           |     0.0%
+ github.com/cloudera/terraform-provider-cdp/resources/opdb         |    23.9%
+ github.com/cloudera/terraform-provider-cdp/utils                  |    43.4%
+ github.com/cloudera/terraform-provider-cdp/utils/test             |    68.8%