Documentation: Missing Example Details from "Single Include"

[DevopsMercenary]

Describe the bug

Documentation at the following line, the example is 'incomplete'

terragrunt/docs/_docs/04_reference/config-blocks-and-attributes.md

Line 527 in 9f5b3f5

_Single include_

Steps To Reproduce

In replicating the example, there are no details for what needs to be in the root /terragrunt.hcl file

Of course, if someone was to assume that nothing was in /terragrunt.hcl the the following error occurrs.

ERRO[0000]   on /Users/greg/workspace/terragrunt/single-include-example/child/terragrunt.hcl line 14:
ERRO[0000]   14:   remote_state_config = include.root.remote_state
ERRO[0000]
ERRO[0000] This object does not have an attribute named "remote_state".

ERRO[0000] /Users/greg/workspace/terragrunt/single-include-example/child/terragrunt.hcl:14,37-50: Unsupported attribute; This object does not have an attribute named "remote_state".
ERRO[0000] Unable to determine underlying exit code, so Terragrunt will exit with error code 1

Inserting the following into /terragrunt.hcl at a minimum at least resolves that errror...

remote_state {
  backend = "s3"
  config = {
    bucket         = "my-terraform-state"
    key            = "${path_relative_to_include()}/terraform.tfstate"
    region         = "us-east-1"
    encrypt        = true
    dynamodb_table = "my-lock-table"
  }
}

Then there is another error, but this gets the point across. Maybe reference a previous example with the necessary code to help guide.