Document Outside Framework Migration Items (Retry, WaitForState, etc)

### Module version

```
v0.14.0
```

### Use-cases

Provider developers migrating from terraform-plugin-sdk may ask about functionality that is intentionally not included in the framework.

For example:

- [`helper/logging.NewLoggingHTTPTransport()`](https://pkg.go.dev/github.com/hashicorp/terraform-plugin-sdk/v2/helper/logging#NewLoggingHTTPTransport)
- [`helper/resource.RetryContext()`](https://pkg.go.dev/github.com/hashicorp/terraform-plugin-sdk/v2/helper/resource#RetryContext)
- [`(helper/resource.StateChangeConf).WaitForStateContext()`](https://pkg.go.dev/github.com/hashicorp/terraform-plugin-sdk/v2/helper/resource#StateChangeConf.WaitForStateContext)

Provider developers should be able to use the existing sdk functionality until better guidance can be given.

### Proposal

I'm not exactly sure the best way to approach this, but maybe include new documentation page(s) in the framework migration guide that discuss these items. Refer any questions to those documentation page(s).

The helper/logging functionality will _likely_ be copied into terraform-plugin-log. The helper/resource bits are more of a gray area (similar to how we've intentionally not included mutex/semaphore capabilities, which can be served with Go standard library or community Go modules).

### References

- https://discuss.hashicorp.com/t/terraform-plugin-framework-what-is-the-replacement-for-waitforstate-or-retrycontext/45538