Add note about Test/MDC events and superevents to search and latest pages

gracedb/templates/search/latest.html

@@ -16,6 +16,8 @@
 {% endblock %}
 
 {% block content %}
+
+<p>Test and MDC events and superevents are not included in the search results by default; see the <a href="/documentation/queries.html">query help</a> for information on how to search for events and superevents in those categories.</p>
 <!-- Search form -->
 <form method="GET" name="search_form">
     <table>

gracedb/templates/search/query.html

@@ -138,6 +138,8 @@ onload="document.search_form.query.focus();"
 
 {% block content %}
 
+<p>Test and MDC events and superevents are not included in the search results by default. See the query help (link below) for information on how to search for events and superevents in those categories.</p>
+
 <form method="GET" name="search_form">
     <table>
         {{ form.as_table }}