Empty objects in schema fail the doc generation

[ovandriyanov]

Terraform allows providers to have empty objects in their schema, but currently terraform-plugin-docs does not recognize such empty fields neither as required, nor optional, nor read-only, and thus cannot generate docs for such providers and raises an error like the following:

no match for empty_block_field, this can happen if you have incompatible schema
defined, for example an optional block where all the child attributes are
computed, in which case the block itself should also be marked computed

I tried to fix it with this patch: #99

[agouil]

I have the same problem with generating the docs for my provider. I have a field defined like the one below as Optional with MaxItems: 1 and tfplugindocs returns the same error message when I run it.

resource "provider_resource" "test" {
  name = "test"
  actions {
    some_action {}
  }
}

I have defined some_action as an empty object because at the same time my provider supports,

resource "provider_resource" "test" {
  name = "test"
  actions {
    another_action {
      field = "foobar"
    }
  }
}

[detro]

Fixed by #134