Fix markdown format

Author: danny50610

BUILDING.md

@@ -98,11 +98,11 @@ Build Requirements
 
   You can download and install mozjpeg using the [vcpkg](https://github.com/Microsoft/vcpkg) dependency manager:
 
-  git clone https://github.com/Microsoft/vcpkg.git
-  cd vcpkg
-  ./bootstrap-vcpkg.sh
-  ./vcpkg integrate install
-  vcpkg install mozjpeg
+      git clone https://github.com/Microsoft/vcpkg.git
+      cd vcpkg
+      ./bootstrap-vcpkg.sh
+      ./vcpkg integrate install
+      vcpkg install mozjpeg
 
   The mozjpeg port in vcpkg is kept up to date by Microsoft team members and community contributors. If the version is out of date, please [create an issue or pull request](https://github.com/Microsoft/vcpkg) on the vcpkg repository.