initial reformatting of comments for Doxygen

shmup.cpp

@@ -1,8 +1,9 @@
-// Hyperbolic Rogue
+// Hyperbolic Rogue -- shoot'em up mode
+// Copyright (C) 2011-2019 Zeno Rogue, see 'hyper.cpp' for details
 
-// Copyright (C) 2011-2018 Zeno Rogue, see 'hyper.cpp' for details
-
-// implementation of the shoot'em up mode
+/** \file shmup.cpp
+ *  \brief shoot'em up mode
+ */
 
 namespace hr {