Main: Add licence header

source/main.rs

@@ -1,3 +1,9 @@
+/*
+ * Copyright (c) 2022, networkException <git@nwex.de>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
 use clap::Parser;
 use indicatif::{ParallelProgressIterator, ProgressBar, ProgressStyle, ProgressFinish};
 use rayon::ThreadPoolBuilder;