hclwrite support for a list of traversals

Hi, I'm working on writing some terraform configuration using `hclwrite` and I'm wondering how to best define an attribute's value as a list of traversals. I see examples for lists via `cty.Value` and `SetAttributeValue` but nothing for traversals. Is it possible with `SetAttributeTraversal` or do I need to resort to `SetAttributeRaw`?

Heres a simplified version of what I have:

```go
package main

import (
"fmt"

"github.com/hashicorp/hcl/v2"
"github.com/hashicorp/hcl/v2/hclwrite"
)

func main() {
f := hclwrite.NewEmptyFile()
rootBody := f.Body()
resBlock := rootBody.AppendNewBlock("resource", []string{"aws_route53_record", "foo"})
resBody := resBlock.Body()
traversal := hcl.Traversal{
hcl.TraverseRoot{Name: "local"},
hcl.TraverseAttr{Name: "name"},
}
resBody.SetAttributeTraversal("name", traversal)
fmt.Printf("%s\n", f.Bytes())
}
```

### HCL Template
```hcl
resource "aws_route53_record" "foo" {
name = local.name
}
```

What I'm trying to achieve is something like:

```hcl
resource "aws_route53_record" "foo" {
name = local.name

records = [local.foo, local.bar]
}
```

I don't see any examples in the docs or any test cases that do this, so any example code for this would be appreciated. thanks!

Start with the hclwrite APIs named in the issue, SetAttributeTraversal and SetAttributeRaw, and compare them with the existing cty.Value list examples. Determine how hclwrite should represent a list containing multiple traversals, with the desired output being records = [local.foo, local.bar].

Written by the indexing model from the issue text.