Add copy for detail page

Author: humitos

readthedocs/templates/projects/environmentvariable_detail.html

@@ -16,6 +16,8 @@
 {% endblock %}
 
 {% block project_edit_content %}
+  <p>These environment variables are available to all build steps.</p>
+
   <form method="post" action="{% url 'projects_environmentvariables_delete' project_slug=project.slug environmentvariable_pk=environmentvariable.pk %}">
     {% csrf_token %}
     <input type="submit" value="{% trans "Delete" %}">