Full, comprehensive documentation is available on the Terraform Registry. API documentation and Developer documentation is also available for non-Terraform or service specific information.
Do you have an existing Cloudflare account (or many!) that you'd like to transition to be managed via Terraform? Check out cf-terraforming which is a tool Cloudflare has built to help dump the existing resources and import them into Terraform.
To contribute, please read the contribution guidelines.
If you would like to provide feedback (not a bug or feature request) on the Cloudflare Terraform provider, you're welcome to via this form.