[Docs] Another round of stylistic fixes.

docs/linux_hw_video_decode.md

-# Enabling hardware 
+# Enabling hardware `<video>` decode codepaths on linux
 
-&lt;video&gt;
+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.
 
- decode codepaths on linux
+*   Install pre-requisites: On Ubuntu Precise, at least, this includes:
 
-Hardware acceleration of video decode on linux is [unsupported](http://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.
+    ```shell
+    sudo apt-get install libtool libvdpau1 libvdpau-dev
+    ```
 
-  * Install pre-requisites: On Ubuntu Precise, at least, this includes:
-```
-sudo apt-get install libtool libvdpau1 libvdpau-dev
-```
+*   Install and configure [libva](http://cgit.freedesktop.org/libva/)
 
-  * Install and configure [libva](http://cgit.freedesktop.org/libva/)
-```
-DEST=${HOME}/apps/libva
-cd /tmp
-git clone git://anongit.freedesktop.org/libva
-cd libva
-git reset --hard libva-1.2.1
-./autogen.sh && ./configure --prefix=${DEST}
-make -j32 && make install
-```
-  * Install and configure the [VDPAU](http://cgit.freedesktop.org/vaapi/vdpau-driver) VAAPI driver
-```
-DEST=${HOME}/apps/libva
-cd /tmp
-git clone git://anongit.freedesktop.org/vaapi/vdpau-driver
-cd vdpau-driver
-export PKG_CONFIG_PATH=${DEST}/lib/pkgconfig/:$PKG_CONFIG_PATH
-export LIBVA_DRIVERS_PATH=${DEST}/lib/dri
-export LIBVA_X11_DEPS_CFLAGS=-I${DEST}/include
-export LIBVA_X11_DEPS_LIBS=-L${DEST}/lib
-export LIBVA_DEPS_CFLAGS=-I${DEST}/include
-export LIBVA_DEPS_LIBS=-L${DEST}/lib
-make distclean
-unset CC CXX
-./autogen.sh && ./configure --prefix=${DEST} --enable-debug
-find . -name Makefile |xargs sed -i 'sI/usr/lib/xorg/modules/driversI${DEST}/lib/driIg'
-sed -i -e 's/_(\(VAEncH264VUIBufferType\|VAEncH264SEIBufferType\));//' src/vdpau_dump.c
-make -j32 && rm -f ${DEST}/lib/dri/{nvidia_drv_video.so,s3g_drv_video.so} && make install
-```
-  * Add to `$GYP_DEFINES`:
-    * `chromeos=1` to link in `VaapiVideoDecodeAccelerator`
-    * `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=${HOME}/apps/libva/lib` in the environment, and with the --no-sandbox command line flag.
-  * If things don't work, a Debug build (to include D\*LOG's) with `--vmodule=*content/common/gpu/media/*=10,gpu_video*=1` might be enlightening.
+    ```shell
+    DEST=${HOME}/apps/libva
+    cd /tmp
+    git clone git://anongit.freedesktop.org/libva
+    cd libva
+    git reset --hard libva-1.2.1
+    ./autogen.sh && ./configure --prefix=${DEST}
+    make -j32 && make install
+    ```
 
-# NOTE THIS IS AN UNSUPPORTED CONFIGURATION AND LIKELY TO BE BROKEN AT ANY POINT IN TIME
+*   Install and configure the
+    [VDPAU](http://cgit.freedesktop.org/vaapi/vdpau-driver) VAAPI driver
 
-This page is purely here to help developers targeting supported HW 
+    ```shell
+    DEST=${HOME}/apps/libva
+    cd /tmp
+    git clone git://anongit.freedesktop.org/vaapi/vdpau-driver
+    cd vdpau-driver
+    export PKG_CONFIG_PATH=${DEST}/lib/pkgconfig/:$PKG_CONFIG_PATH
+    export LIBVA_DRIVERS_PATH=${DEST}/lib/dri
+    export LIBVA_X11_DEPS_CFLAGS=-I${DEST}/include
+    export LIBVA_X11_DEPS_LIBS=-L${DEST}/lib
+    export LIBVA_DEPS_CFLAGS=-I${DEST}/include
+    export LIBVA_DEPS_LIBS=-L${DEST}/lib
+    make distclean
+    unset CC CXX
+    ./autogen.sh && ./configure --prefix=${DEST} --enable-debug
+    find . -name Makefile |xargs sed -i 'sI/usr/lib/xorg/modules/driversI${DEST}/lib/driIg'
+    sed -i -e 's/_(\(VAEncH264VUIBufferType\|VAEncH264SEIBufferType\));//' src/vdpau_dump.c
+    make -j32 && rm -f ${DEST}/lib/dri/{nvidia_drv_video.so,s3g_drv_video.so} && make install
+    ```
 
-&lt;video&gt;
+*   Add to `$GYP_DEFINES`:
+    *   `chromeos=1` to link in `VaapiVideoDecodeAccelerator`
+    *   `proprietary_codecs=1 ffmpeg_branding=Chrome` to allow Chrome to play
+        h.264 content, which is the only codec VAVDA knows about today.
+*   Re-run gyp (`./build/gyp_chromium` or `gclient runhooks`)
+*   Rebuild chrome
+*   Run chrome with `LD_LIBRARY_PATH=${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.
 
- decode platforms be more effective.  Do not expect help if this setup fails to work.
+**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.