website/docs/plugin: Update the Which SDK page to include two new framework-only features (#65)

Reference: hashicorp/terraform-plugin-framework#396
Reference: hashicorp/terraform-plugin-framework#409

These were included in the terraform-plugin-framework v0.10.0 release and are features not available in terraform-plugin-sdk/v2.

Author: bflad

website/docs/plugin/which-sdk.mdx

@@ -41,6 +41,8 @@ should consider using the framework if you would benefit from the ability to:
 * Use nested attributes.
 * Use any type as the elements of a map.
 * Tell when an optional and computed field has been removed from a config.
+* Implement schema-based validation that is relative to the current attribute or applies to any list, map, or set element.
+* Return warning or error diagnostics during resource destruction.
 
 ## Do You Need Any Features That the Framework Doesn't Provide (Yet)?