DIV-862: Adding descriptive helper text to plan coverage question

edivorce/apps/core/templates/question/06_children_payor_medical.html

@@ -30,6 +30,7 @@
 
     <div class="question-well" id="who_plan_is_coverage_under" hidden>
         <h3>Whose plan is the coverage under?</h3>
+        <p>Please check all that apply:</p>
         <div class="checkbox-group">
             <div class="checkbox"><label>{% input_field type="checkbox" name="whose_plan_is_coverage_under" value="My plan" %} My plan</label></div>
             <div class="checkbox"><label>{% input_field type="checkbox" name="whose_plan_is_coverage_under" value="Spouse" %} Spouse</label></div>