Add note about protocol v6 to upgrade guide

docs/guides/v3-upgrade-guide.md

@@ -8,7 +8,6 @@ description: |-
 # Upgrading to v3.0.0 of the Helm provider
 
 
-
 This guide covers the changes introduced in v3.0.0 of the Helm provider and what you may need to do to upgrade your configuration.
 
 ## Changes in v3.0.0
@@ -20,6 +19,10 @@ The Helm provider has been migrated from the legacy [Terraform Plugin SDKv2](htt
 - **Blocks to Nested Objects**: Blocks like `kubernetes`, `registry`, and `experiments` are now represented as nested objects.
 - **List Syntax for Nested Attributes**: Attributes like `set`, `set_list`, and `set_sensitive` in `helm_release` and `helm_template` are now lists of nested objects instead of blocks.
 
+### Terraform Version Compatability 
+
+The new framework code uses [Terraform Plugin Protocol Version 6](https://developer.hashicorp.com/terraform/plugin/terraform-plugin-protocol#protocol-version-6) which is compatible with Terraform versions 1.0 and aboove. Users of earlier versions of Terraform can continue to use the Helm provider by pinning their configuration to the 2.x version. 
+
 ---
 
 ### Changes to Provider Attributes