Formatting support for HCL

historically I'd used vscode's `"files.associations": {}` setting to tie `hcl` files to the terraform extension to get simple formatting support, like so:

```json
{
"files.associations": {
"*.hcl": "terraform"
}
}
```

if there isn't already a plan to add formatting support to this extension I'd like to formally request one!

No files, tests, or entry points are named. Start by reviewing the vscode-hcl extension and the issue discussion to determine the intended formatting scope and existing plans. Done means the extension provides formatting support for HCL files in VS Code.

Written by the indexing model from the issue text.