Added a file about multiple languages in dom0

docs/localization/multi-language-support-dom0.md

@@ -0,0 +1,63 @@
+Using multiple languages in dom0
+================================
+
+Installing additional languages
+-------------------------------
+
+Switching languages is pretty easy in your domUs. However, in dom0, there's only
+English available after installation if no additional languages have been installed.
+To install more languages in dom0, use the following command:
+
+~~~
+sudo qubes-dom0-update glibc-langpack-LANGUAGE
+~~~
+
+Note that `LANGUAGE` should be a valid language code, e.g. `en` for English, `de` for
+German, `it` for Italian and so on.
+
+You can check which languages are available on your system using:
+
+~~~
+localectl list-locales
+~~~
+
+Setting a language globally
+---------------------------
+
+If you want to switch your whole dom0 from English to some other language,
+edit the file `/etc/locale.conf` to include your language code for the `LANG=` value.
+For example, to change your dom0 to Italian, the file `/etc/locale.conf` should contain:
+
+~~~
+LANG="it_IT.UTF-8"
+~~~
+
+Important: Using some language other than English is not officially supported, i.e. you
+might still get a lot of English content which has not been translated to your desired language.
+
+Setting only some formats
+-------------------------
+
+If you want just change some format specifiers, you can add the `LC_*` identifier
+in the same file, below the `LANG=` code. Avoid the `LC_ALL` identifier, because it overwrites
+all previous settings! For example, to use German time formats but still use the English
+language as default for anything else, you would write the following in `/etc/locale.conf`:
+
+~~~
+LANG="en_US.UTF-8"
+LC_TIME="de_DE.UTF-8"
+~~~
+
+Those codes must be supported by your dom0 (check with `localectl list-locales`).
+
+After you finished editing, check your new setup with `localectl status`. You might need
+to logout and login back again to enable your changes in the environment (e.g. in the window
+manager or its applets).
+
+You might also want to inspect the changes introduced by adding/editing one `LC_*` rule
+in the config file. Use `locale -k $rule` for this purpose, e.g. `locale -k LC_TIME` to
+show the formats exported by the setting of the `LC_TIME`.
+
+If you see "broken characters" like `<60>` somewhere, check the encoding of the affected
+application. The default terminal emulator in dom0 does not use Unicode as default
+encoding and therefore has some problems when it's not adjusted accordingly.