add argparse.hh initial skeleton

ostd/argparse.hh

@@ -0,0 +1,13 @@
+/* Argument parser.
+ *
+ * This file is part of OctaSTD. See COPYING.md for futher information.
+ */
+
+#ifndef OSTD_ARGPARSE_HH
+#define OSTD_ARGPARSE_HH
+
+namespace ostd {
+
+} /* namespace ostd */
+
+#endif