Fix name

Author: kou

ruby/red-arrow-format/lib/arrow-format/type.rb

@@ -305,7 +305,7 @@ class TimestampType < TemporalType
     attr_reader :unit
     attr_reader :timezone
     def initialize(unit, timezone)
-      super("Temporal")
+      super("Timestamp")
       @unit = unit
       @timezone = timezone
     end