docu: adding docu modules

- Controllers
- Internals
- Utilities
- Examples

Author: torbjoernk

include/pfasst.hpp

@@ -23,4 +23,21 @@ namespace pfasst
   }
 } // ::pfasst
 
+
+/**
+ * @defgroup Controllers
+ *   Controllers represent the main entry point of PFASST++ as they ensemble the central algorithmic
+ *   logic of PFASST and related algorithms.
+ *
+ * @defgroup Internals
+ *   Entities listed in this module are ment to be for internal use only and should not be used
+ *   outside of PFASST++ itself.
+ *
+ * @defgroup Utilities
+ *   General utility functions not directly related to PFASST++ but also handy in user code.
+ *
+ * @defgroup Examples
+ *   A few different examples demonstrating the use and functionality of PFASST++.
+ */
+
 #endif