docs/getting-started: Replace underscores in aws_s3_bucket name in dependencies example

website/intro/getting-started/dependencies.html.md

@@ -156,7 +156,7 @@ resource "aws_s3_bucket" "example" {
   # NOTE: S3 bucket names must be unique across _all_ AWS accounts, so
   # this name must be changed before applying this example to avoid naming
   # conflicts.
-  bucket = "terraform_getting_started_guide"
+  bucket = "terraform-getting-started-guide"
   acl    = "private"
 }