games/mkfile: add sudoku
 [rsc] --rw-rw-r-- M 1217231 jmk sys 595 Feb 17 14:03 sys/src/games/mkfile
	/n/sourcesdump/2006/0217/plan9/sys/src/games/mkfile:15,20 - 
	/n/sourcesdump/2006/0218/plan9/sys/src/games/mkfile:15,21
	  DIRS=\
	  	mahjongg\
	  	sokoban\
	+ 	sudoku\
	  
	  4s.$O 5s.$O xs.$O:	xs.h
	  $O.4s $O.5s: xs.$O