Use expandable details in mails tldr;)s

Change-Id: Ie35ef89b2ffc3c6a53ddb8872f9f745a8ec431d9
diff --git a/templates/email.php b/templates/email.php
index c55c38e..537920d 100644
--- a/templates/email.php
+++ b/templates/email.php
@@ -1,9 +1,9 @@
 <?php
 $REGISTRATION_INFORMATION = "
-<h3>Registration information</h3>
-<p>
+<details>
+<summary>Registration details</summary>
 {{usertable}}
-</p>
+</details>
 ";
 
 $WELCOME_TEMPLATE = (object)[
@@ -24,7 +24,7 @@
         "text"    => "To complete your registration please paste this to your browser: {{url}}",
         "html" => "<html><body>
                 <p>Dear {{full_name}},</p>
-                <p>Please check the information below and click on the confirm button to complete your " . $SERVICE_ACRONYM . " registration:</p>"
+                <p>Please check the registration details below and click on the confirm button to complete your " . $SERVICE_ACRONYM . " registration:</p>"
                 . $REGISTRATION_INFORMATION . "
                 <p>
                 If you did not request this registration, please ignore this email.