plugin: Include terraform-plugin-framework in protocol version 5 impl…

…ementations

Reference: hashicorp/terraform-plugin-framework#368

terraform-plugin-framework v0.9.0 will natively support Terraform Plugin Protocol version 5, which simplifies implementations which must support Terraform CLI 0.12 or later, or those migrating from terraform-plugin-sdk/v2 to the framework and using terraform-plugin-mux. Other plugin documentation is being separately updated.

website/docs/plugin/how-terraform-works.mdx

@@ -138,6 +138,7 @@ Protocol version 5 is compatible with Terraform CLI version 0.12 and later.
 
 Implementations include:
 
+* [terraform-plugin-framework](/plugin/framework): A higher-level SDK that makes Terraform provider development easier by abstracting implementation details.
 * [terraform-plugin-sdk/v2](/plugin/sdkv2): A higher-level SDK that makes Terraform provider development easier by abstracting implementation details.
 * [terraform-plugin-go tf5server](https://pkg.go.dev/github.com/hashicorp/terraform-plugin-go/tfprotov5/tf5server): A lower-level SDK to develop Terraform providers for more advanced use cases.
 * [tf6to5server](/plugin/mux/translating-protocol-version-6-to-5): A package to translate protocol version 6 providers into protocol version 5.