Ubuntu 18.04: Install locales

This matches the Debian instructions.

Closes #7616

Ubuntu-18.04-Root-on-ZFS.md

@@ -227,17 +227,16 @@ Customize this file if the system is not a DHCP client.
 
 4.5 Configure a basic system environment:
 
-    # locale-gen en_US.UTF-8
+    # ln -s /proc/self/mounts /etc/mtab
+    # apt update
+
+    # apt install --yes locales
+    # dpkg-reconfigure locales
 
 Even if you prefer a non-English system language, always ensure that `en_US.UTF-8` is available.
 
-    # echo LANG=en_US.UTF-8 > /etc/default/locale
-
     # dpkg-reconfigure tzdata
 
-    # ln -s /proc/self/mounts /etc/mtab
-    # apt update
-
     If you prefer nano over vi, install it:
     # apt install --yes nano