doc/_templates/layout.html

{% extends "!layout.html" %}
{% block document %}
  {% if is_release %}
    <div class="wy-alert wy-alert-danger">
      The <a href="/{{ pagename }}.html">latest development version</a>
      of this page may be more current than this released {{ version }} version.
    </div>
  {% endif %}
  {{ super() }}
{% endblock %}