Quick howto: fix missing keyboard layout in Xfce settings.

This is not a deep-dive into how keyboard layouts are configured. This is just a "note to self" in case I ever wonder "how the hell did I fix that"?

The problem: my prefered keyboard layout doesn't show up in Xfce's keyboard settings tool. setxkbmap ro basic works, but gets reset after a while.

The solution: edit /usr/share/X11/xkb/rules/evdev.xml. Find the Romanian language section. On Xubuntu 22.04 it looks like this:

<layout>
  <configItem>
    <name>ro</name>
    <!-- Keyboard indicator for Romanian layouts -->
    <shortDescription>ro</shortDescription>
    <description>Romanian</description>
    <languageList>
      <iso639Id>ron</iso639Id>
    </languageList>
  </configItem>
  <variantList>
    <variant>
      <configItem>
        <name>std</name>
        <description>Romanian (standard)</description>
      </configItem>
    </variant>
    <variant>
      <configItem>
        <name>winkeys</name>
        <description>Romanian (Windows)</description>
      </configItem>
    </variant>
  </variantList>
</layout>

<variant>
  <configItem>
    <name>basic</name>
    <description>Romanian (basic)</description>
  </configItem>
</variant>