Booting/README.md updated

Booting/README.md

@@ -5,3 +5,4 @@ couple of posts which describes full cycle of the kernel loading:
 
 * [From the bootloader to kernel](http://0xax.gitbooks.io/linux-insides/content/Booting/linux-bootstrap-1.html) - describes all stages from turning on the computer before the first instruction of the kernel;
 * [First steps in the kernel setup code](http://0xax.gitbooks.io/linux-insides/content/Booting/linux-bootstrap-2.html) - describes first steps in the kernel setup code. You will see heap initialization, querying of different parameters like EDD, IST and etc...
+* [Video mode initialization and transition to protected mode](http://0xax.gitbooks.io/linux-insides/content/Booting/linux-bootstrap-3.html) - describes video mode initialization in the kernel setup code and transition to protected mode.