Make the instructions for downloading the ARM compiler easier to copy and paste.

Change-Id: If78cba6abc36999488981db2a12b039024c757df
Reviewed-on: https://boringssl-review.googlesource.com/6391
Reviewed-by: Brian Smith <brian@briansmith.org>
Reviewed-by: David Benjamin <davidben@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>

BUILDING.md

diff --git a/BUILDING.md b/BUILDING.md
index 7d4eac4..02f8f11 100644
--- a/BUILDING.md
+++ b/BUILDING.md
@@ -27,14 +27,14 @@
   * [Go](https://golang.org/dl/) is required. If not found by CMake, the go
     executable may be configured explicitly by setting `GO_EXECUTABLE`.
 
-  * If you change crypto/chacha/chacha_vec.c, you will need the
+  * If you change crypto/chacha/chacha\_vec.c, you will need the
     arm-linux-gnueabihf-gcc compiler:
 
     ```
-    $ wget https://releases.linaro.org/14.11/components/toolchain/binaries/arm-linux-gnueabihf/gcc-linaro-4.9-2014.11-x86_64_arm-linux-gnueabihf.tar.xz
-    $ echo bc4ca2ced084d2dc12424815a4442e19cb1422db87068830305d90075feb1a3b  gcc-linaro-4.9-2014.11-x86_64_arm-linux-gnueabihf.tar.xz | sha256sum -c
-    $ tar xf gcc-linaro-4.9-2014.11-x86_64_arm-linux-gnueabihf.tar.xz
-    $ sudo mv gcc-linaro-4.9-2014.11-x86_64_arm-linux-gnueabihf /opt/
+    wget https://releases.linaro.org/14.11/components/toolchain/binaries/arm-linux-gnueabihf/gcc-linaro-4.9-2014.11-x86_64_arm-linux-gnueabihf.tar.xz && \
+    echo bc4ca2ced084d2dc12424815a4442e19cb1422db87068830305d90075feb1a3b  gcc-linaro-4.9-2014.11-x86_64_arm-linux-gnueabihf.tar.xz | sha256sum -c && \
+    tar xf gcc-linaro-4.9-2014.11-x86_64_arm-linux-gnueabihf.tar.xz && \
+    sudo mv gcc-linaro-4.9-2014.11-x86_64_arm-linux-gnueabihf /opt/
     ```
 
 ## Building