rms-support-letter.github.io/_includes/translations.html

<div class="translations">
  <p>Translations:</p>
  <a class="translation" href='/'>🇺🇸</a>
  {% for translation in site.translations %}
    <a class="translation" href="{{ translation.url }}">
      {%- assign langcode = translation.locale | split: "_" | last | downcase -%}
      {%- assign c1 = langcode | slice: 0, 1 -%}
      {%- assign c2 = langcode | slice: 1, 1 -%}
      {{- site.data.emoji[c1] -}}{{- site.data.emoji[c2] -}}
    </a>
  {% endfor %}
</div>