Consider Tuple support for doc generator

### Terraform CLI and terraform-plugin-docs Versions

`github.com/hashicorp/terraform-plugin-docs v0.18.0`

### Use Cases or Problem Statement

Bubbling up from this comment https://github.com/hashicorp/terraform-plugin-go/issues/267#issuecomment-1494874479 and a TODO in an error message here: https://github.com/hashicorp/terraform-plugin-docs/blob/6b686eefb31bc0d7e4e7a3a71952e98e882babef/schemamd/render.go#L86

Tuple support is currently not implemented in `tfplugindocs` because neither SDKv2 or Plugin Framework support schema attributes as tuples. Despite this, it's still possible to write a provider that has tuple's in the schema with [`terraform-plugin-go`](https://github.com/hashicorp/terraform-plugin-go).

This issue can be used to capture any interest in adding render logic for Tuples in `tfplugindocs`.

### Proposal

TBD

### How much impact is this issue causing?

Low

### Additional Information

- https://developer.hashicorp.com/terraform/language/expressions/type-constraints#tuple
- Framework issue closed due to lack of interest: https://github.com/hashicorp/terraform-plugin-framework/issues/54

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