CDPT-1069 Add link to maintenance page (#700)

Author: vertism

app/views/errors/maintenance.html.erb

@@ -2,8 +2,8 @@
 
 <div class="govuk-grid-row">
   <div class="govuk-grid-column-two-thirds">
-    <h1 class="govuk-heading-xl"><%=t '.heading' %></h1>
+    <h1 class="govuk-heading-xl"><%= t '.heading' %></h1>
 
-    <p class="govuk-body"><%=t '.lead_text' %></p>
+    <p class="govuk-body"><%= t '.lead_text_html' %></p>
   </div>
 </div>

config/locales/en/errors.yml

@@ -127,4 +127,9 @@ en:
     maintenance:
       page_title: Service Maintenance
       heading: Service Maintenance
-      lead_text: This service is currently unavailable
+      lead_text_html: |
+        This service is currently unavailable
+        <p>For guidance see</p>
+        <p>
+          <a href="https://www.gov.uk/tell-employer-or-college-about-criminal-record">Check if you need to tell someone about your criminal record: When you need to tell someone about your criminal record - GOV.UK (www.gov.uk)</a>
+        </p>