Make the readme more readable.

README.md

@@ -56,6 +56,7 @@ How to build it?
 ----------------
 
  0. You have to build cURL before building WinGup:
+ ```
     a. Open VS2015 Native Tool Command for 32/64 bits
     b. go to curl winbuild directory:
        cd <your wingup source path>\curl\winbuild
@@ -64,7 +65,7 @@ How to build it?
        x64 debug: nmake /f Makefile.vc mode=dll vc=14 RTLIBCFG=static DEBUG=yes MACHINE=x64
        x86 release: nmake /f Makefile.vc mode=dll vc=14 RTLIBCFG=static MACHINE=x86
        x86 debug: nmake /f Makefile.vc mode=dll vc=14 RTLIBCFG=static DEBUG=yes MACHINE=x86
-
+```
  1. Open [`vcproj\GUP.vcxproj`](https://github.com/gup4win/wingup/blob/master/vcproj/GUP.vcxproj)
 
  2. Build WinGup [like a normal Visual Studio project](https://msdn.microsoft.com/en-us/library/7s88b19e.aspx) with VS2015