Add make clean and remove to readme

Author: meatballs

README.rst

@@ -56,4 +56,17 @@ You should now have a `bin` directory containing the the executable file,
 `tourexec`, which you can run::
 
 	$ cd ../bin
-	$ ./tourexec
+	$ ./tourexec
+
+Cleanup
+-------
+
+Compiling the executable file will create some intermediary object files in an
+`obj` directory. These can safely be removed using::
+
+	$ make clean
+
+There is also a command to remove the executable itself as well as the object
+files::
+
+	$ make remove