feat(opac): began module public interface definition

src/opac/public/opac.h

@@ -0,0 +1,23 @@
+#ifndef OPAC_H
+#define OPAC_H
+
+#include <string>
+#include <map>
+#include "DObject.h"
+
+/**
+  * @breif initlaize the opacity module
+  * @param args: a hash map of all arguments needed to intialize opac
+  * @return error code in a DObject 
+**/
+DObject initlaize_opac(const std::map<std::string, DObject>& args);
+
+
+/**
+  * @breif opacity given a temperature, density, and composition
+  * @param args: a hash map of all arguments needed to calculate opac
+  * @return error code in a DObject 
+**/
+DObject
+
+#endif