add how to use mklib.bat and mk.bat for win

mklib.bat

@@ -1,4 +1,7 @@
 @echo off
-nasm -f win64 -D_WIN64 src\asm\low_x86-64.asm
+rem nasm -f win64 -D_WIN64 src\asm\low_x86-64.asm
+rem cl /DNOMINMAX /Ox /DNDEBUG /W4 /Zi /EHsc /c -I ./include -I../xbyak -I../cybozulib/include -I../cybozulib_ext/include src\fp.cpp
+rem lib /OUT:lib\mcl.lib /nodefaultlib fp.obj src\asm\low_x86-64.obj
+
 cl /DNOMINMAX /Ox /DNDEBUG /W4 /Zi /EHsc /c -I ./include -I../xbyak -I../cybozulib/include -I../cybozulib_ext/include src\fp.cpp
-lib /OUT:lib\mcl.lib /nodefaultlib fp.obj src\asm\low_x86-64.obj
+lib /OUT:lib\mcl.lib /nodefaultlib fp.obj

readme.md

@@ -62,6 +62,15 @@ make ARCH=x86 CFLAGS_USER="-I <lib32>/include" LDFLAGS_USER="-L <lib32>/lib -Wl,
 ```
 
 ## Build for 64-bit Windows
+1) make library
+```
+>mklib.bat
+```
+2) make exe binary of sample\pairing.cpp
+```
+>mk sample\pairing.cpp
+```
+
 open mcl.sln and build or if you have msbuild.exe
 ```
 msbuild /p:Configuration=Release