Make some small tweaks to the build instructions.

docs/linux_arch_build_instructions.md

Index: docs/linux_arch_build_instructions.md
diff --git a/docs/linux_arch_build_instructions.md b/docs/linux_arch_build_instructions.md
index 87bfe8b039ea9535b12e9fdf51a7de07e9f67ca3..9d3bcf0f6199d63ec615ab4155c110bc811763b5 100644
--- a/docs/linux_arch_build_instructions.md
+++ b/docs/linux_arch_build_instructions.md
@@ -3,18 +3,21 @@
 Generally speaking, follow the [Linux Build Instructions](linux_build_instructions.md).
 However, do the following instead to install the build dependencies:
 
-## Install the build dependencies:
+## Install the build dependencies
 
 Most of these packages are probably already installed since they're often used,
-and the parameter --needed ensures that packages up to date are not reinstalled.
+and the `--needed` parameter ensures that up-to-date packages are not
+reinstalled.
 
-    sudo pacman -S --needed python perl gcc gcc-libs bison flex gperf pkgconfig \
-    nss alsa-lib gconf glib2 gtk2 nspr ttf-ms-fonts freetype2 cairo dbus \
-    libgnome-keyring
+```shell
+$ sudo pacman -S --needed python perl gcc gcc-libs bison flex gperf pkgconfig \
+nss alsa-lib gconf glib2 gtk2 nspr ttf-ms-fonts freetype2 cairo dbus \
+libgnome-keyring
+```
 
 For the optional packages on Arch Linux:
 
-*   php-cgi is provided with pacman
-*   wdiff is not in the main repository but dwdiff is. You can get wdiff in
-    AUR/yaourt
-*   sun-java6-fonts do not seem to be in main repository or AUR.
+*   `php-cgi` is provided with `pacman`
+*   `wdiff` is not in the main repository but `dwdiff` is. You can get `wdiff`
+    in AUR/`yaourt`
+*   `sun-java6-fonts` do not seem to be in main repository or AUR.