fix: misc batch enrollment issues

lms/templates/emails/payment_reminder.html

@@ -0,0 +1,19 @@
+<div>
+    <p>{{ _('Hi') }} {{ billing_name }},</p>
+    <p>{{ _('We noticed that you started enrolling in the') }} {{ type }} {{ title }} {{ _('but didn’t complete your payment') }}.</p>
+    <p>
+        {{ _("We have a limited number of seats, and they won't be available for long!")}}
+    </p>
+    <p>
+        {{ _("Don’t miss this opportunity to enhance your skills. Click below to complete your enrollment") }}:
+    </p>
+    <p>
+        <a href="{{ link }}">👉 Complete Your Enrollment</a>
+    </p>
+    <p>
+        {{ _("If you have any questions or need assistance, feel free to reach out to our support team.") }}
+    </p>
+    <p>
+        {{ __("Looking forward to seeing you enrolled!") }}
+    </p>
+</div>