Fix that a property's custom model can take a description

[sergiobayona]

    class Routes
      include EasyTalk::Model

      def self.name
        'system_routes'
      end

      define_schema do
        property :name, String, description: 'The name of the route'
        property :path, String, description: 'The path to the route'
        property :parameters, Params, description: 'The parameters for the route' # <-- description does not appear in the json schema
        property :title, String, description: 'A short description of the conversation'
      end
    end

[sergiobayona]

prop = Propery.new(:name, custom_class, title: 'Custom Class', description: 'some description').as_json

calls type.schema which returns the schema of custom_class

see https://github.com/sergiobayona/easy_talk/blob/main/lib/easy_talk/property.rb#L87

ignoring the outer scope