update lab1-8 codes and docs. now version is 0.2

code/lab8/kern/init/init.c

@@ -13,9 +13,10 @@
 #include <swap.h>
 #include <proc.h>
 #include <fs.h>
+#include <kmonitor.h>
 
 int kern_init(void) __attribute__((noreturn));
-
+void grade_backtrace(void);
 static void lab1_switch_test(void);
 
 int