:doc: update README.md

README.md

@@ -127,3 +127,5 @@ fslongjin
 - ACPI_6_3_final_Jan30
 
 - the GNU GRUB manual
+
+- Intel® 64 and IA-32 Architectures Software Developer’s Manual

README_EN.md

@@ -126,3 +126,5 @@ This project refers to the following materials. I sincerely give my thanks to th
 - ACPI_6_3_final_Jan30
 
 - the GNU GRUB manual
+
+- Intel® 64 and IA-32 Architectures Software Developer’s Manual