Clarified purpose and usage of generate_code.pl

Added comments to explain purpose and usage of generate_code.pl

tests/scripts/generate_code.pl

diff --git a/tests/scripts/generate_code.pl b/tests/scripts/generate_code.pl
index 1c7a281..581320e 100755
--- a/tests/scripts/generate_code.pl
+++ b/tests/scripts/generate_code.pl
@@ -1,5 +1,12 @@
 #!/usr/bin/env perl
+
+# generate_code.pl
 #
+# Generates the test suite code given inputs of the test suite directory that
+# contain the test suites, and the test suite file names for the test code and
+# test data.
+#
+# Usage: generate_code.pl <suite dir> <code file> <data file> [main code file]
 
 use strict;