Update src/uu/dd/src/datastructures.rs
Adds project header to conversion_tables.rs
+// This file is part of the uutils coreutils package.
+//
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+
+// spell-checker:ignore (ToDO) ctable noerror
+
use crate::conversion_tables::*;
use std::error::Error;
