Adding archlinux packaging documentation

packaging/archlinux/README.archlinux

@@ -0,0 +1,25 @@
+Docker on Arch
+==============
+
+The AUR lxc-docker and lxc-docker-git packages handle building docker on Arch
+linux.  The PKGBUILD specifies all dependencies, build, and packaging steps.
+
+Dependencies
+============
+
+The only buildtime dependencies are git and go which are available via pacman.
+The -s flag can be used on makepkg commands below to automatically install
+these dependencies.
+
+Building Package
+================
+
+Download the tarball for either AUR packaged to a local directory.  In that
+directory makepkg can be run to build the package.
+
+# Build the binary package
+makepkg
+
+# Build an updated source tarball
+makepkg --source
+