Merge pull request #24 from authsignal/update-readme

Update readme with link to docs on Terraform registry

README.md

@@ -1,3 +1,5 @@
-This is Authsignal's Terraform provider.
+# Introduction
+
+This is Authsignal's Terraform provider. Documentation can be found on the [official Terraform registry](https://registry.terraform.io/providers/authsignal/authsignal/latest/docs).
 
 This provider is based on HashiCorp's HashiCups example which can be [found here](https://github.com/hashicorp/terraform-provider-hashicups).