## A variable can be sensitive

When a variable is sensitive all string-values from that variable will be
obfuscated from Packer's output :

```hcl
# var-foo.pkr.hcl
variable "foo" {
    sensitive = true
    default   = {
        key = "SECR3TP4SSW0RD"
    }
}
```

```shell-session
$ packer inspect var-foo.pkr.hcl
Packer Inspect: HCL2 mode

> input-variables:
var.foo: "{\n  \"key\" = \"<sensitive>\"\n }"
...
```
