Use $(EXECUTABLE).cpp for default main() file if project*.cpp is not found.

Makefile

@@ -49,7 +49,7 @@ OBJECTS     = $(SOURCES:%.cpp=%.o)
 
 # TODO
 # If main() is in a file named project*.cpp, use the following line
-PROJECTFILE = $(or $(wildcard project*.cpp), nomain.cpp)
+PROJECTFILE = $(or $(wildcard project*.cpp), $(EXECUTABLE).cpp)
 # TODO
 # If main() is in another file delete line above, edit and uncomment below
 #PROJECTFILE = mymainfile.cpp