docs: Updated the docs/index.md for registries.

docs/index.md

@@ -47,7 +47,7 @@ functionality.
 
 The goal of this provider is not to call any APIs, but to provide
 pre-built functions in the form of _Data Sources_ or _Provider
-Functions_ (1.8).
+Functions_ (Terraform 1.8; OpenTofu 1.7).
 
 ~> While it’s common knowledge that Terraform is great at standing up and managing Cloud infrastructure, it’s also good at running _anything with an API_. People regularly manage [code repositories], [DNS records], [feature flags], [identity and access management], [content delivery], [passwords], [monitoring], [alerts], [zero trust network access], [cryptographic signatures], and can even [order a pizza]. This provider is more analogous to HashiCorp’s _utility_ providers such as [local], [external], and [archive].
 
@@ -57,12 +57,12 @@ Built using the [Terraform Plugin Framework][TPF], which speaks [Terraform Proto
 
 | Testing type | Details           | Description                                                                    |
 |--------------|-------------------|--------------------------------------------------------------------------------|
-| integration  | Terraform 1.0–1.8 | Executes the provider with this release, pulling from `registry.terraform.io`. |
-| integration  | OpenTofu 1.6–1.7  | Executes the provider with this release, pulling from `registry.opentofu.org`. |
-| unit         | Go 1.21–1.22      | Tests using these versions.                                                    |
-| mutation     | Go 1.21–1.22      | Tests using these versions.                                                    |
-| fuzz         | Go 1.21–1.22      | Tests using these versions.                                                    |
-| terratest    | Go 1.21–1.22      | Tests using these versions.                                                    |
+| integration  | Terraform 1.0–1.9 | Executes the provider with this release, pulling from `registry.terraform.io`. |
+| integration  | OpenTofu 1.6–1.8  | Executes the provider with this release, pulling from `registry.opentofu.org`. |
+| unit         | Go 1.22–1.23      | Tests using these versions.                                                    |
+| mutation     | Go 1.22–1.23      | Tests using these versions.                                                    |
+| fuzz         | Go 1.22–1.23      | Tests using these versions.                                                    |
+| terratest    | Go 1.22–1.23      | Tests using these versions.                                                    |
 
 ## Setting-up the provider
 
@@ -91,10 +91,30 @@ provider "corefunc" {
 
 For users of Terraform 1.8/OpenTofu 1.7 (and newer), all of the the _Data Source_ and _Provider Function_ implementations are available. Their implementations (inputs, outputs) are consistent with each other, and will always return the same outputs from the same imputs. _Provider Functions_ require version 1.4.0 (or later) of this provider.
 
+#### `versions.tf`
+
 ```terraform
 terraform {
   required_version = "~> 1.8" # Terraform
-  # required_version = "~> 1.7" # OpenTofu
+
+  required_providers {
+    corefunc = {
+      source  = "northwood-labs/corefunc"
+      version = "~> 1.4"
+    }
+  }
+}
+
+provider "corefunc" {
+  # There are no configuration options
+}
+```
+
+#### `versions.tofu`
+
+```terraform
+terraform {
+  required_version = "~> 1.7"
 
   required_providers {
     corefunc = {