[Docs] fixes

docs/linux_hw_video_decode.md

-# Enabling hardware `<video>` decode codepaths on linux
+# Enabling hardware <video> decode codepaths on linux
 
 Hardware acceleration of video decode on Linux is
 [unsupported](https://crbug.com/137247) in Chrome for user-facing builds. During
 development (targeting other platforms) it can be useful to be able to trigger
 the code-paths used on HW-accelerated platforms (such as CrOS and win7) in a
 linux-based development environment. Here's one way to do so, with details based
 on a gprecise setup.
 
 *   Install pre-requisites: On Ubuntu Precise, at least, this includes:
 
@@ skipping 40 matching lines @@
     *   `proprietary_codecs=1 ffmpeg_branding=Chrome` to allow Chrome to play
         h.264 content, which is the only codec VAVDA knows about today.
 *   Re-run gyp (`./build/gyp_chromium` or `gclient runhooks`)
 *   Rebuild chrome
 *   Run chrome with `LD_LIBRARY_PATH=${HOME}/apps/libva/lib` in the environment,
     and with the `--no-sandbox` command line flag.
 *   If things don't work, a Debug build (to include D\*LOG's) with
     `--vmodule=*content/common/gpu/media/*=10,gpu_video*=1` might be
     enlightening.
 
-**NOTE THIS IS AN UNSUPPORTED CONFIGURATION AND LIKELY TO BE BROKEN AT ANY
-POINT IN TIME**
+** note
+NOTE THIS IS AN UNSUPPORTED CONFIGURATION AND LIKELY TO BE BROKEN AT ANY
+POINT IN TIME
+**
 
 This page is purely here to help developers targeting supported HW `<video>`
 decode platforms be more effective. Do not expect help if this setup fails to
 work.