A directive @name on ... definition: where a custom directive may be
applied and whether it may repeat.
Summary
Types
@type t() :: %TypedGql.Language.DirectiveDefinition{ arguments: [TypedGql.Language.InputValueDefinition.t()], description: String.t() | nil, directives: [TypedGql.Language.Directive.t()], loc: map(), locations: [atom()], name: String.t() | nil, repeatable: boolean() }