Update SUMMARY.md

SUMMARY.md

@@ -17,11 +17,11 @@
     * [Scheduler initialization](Initialization/linux-initialization-8.md)
     * [RCU initialization](Initialization/linux-initialization-9.md)
     * [End of initialization](Initialization/linux-initialization-10.md)
+* [Interrupts](interrupts/README.md)
+    * [Introduction](interrupts/interrupts-1.md)
 * [Memory management](mm/README.md)
     * [Memblock](mm/linux-mm-1.md)
     * [Fixmaps and ioremap](mm/linux-mm-2.md)
-* [Interrupts](interrupts/README.md)
-    * [Introduction]() 
 * [vsyscalls and vdso]()
 * [SMP]()
 * [Concepts](Concepts/README.md)