add black friday coupon code

app/dashboard/templates/dashboard/pricing.html

@@ -74,6 +74,16 @@
         (e.g. IBAN transfer).
       </div>
 
+      <div class="alert alert-info">
+        Black Friday Deal: 50% off on the yearly plan ($15/year instead of $29.99/year) with the coupon code
+        <em data-toggle="tooltip"
+            title="Click to copy"
+            class="clipboard"
+            data-clipboard-text="BLACKFRIDAY">BLACKFRIDAY</em>
+        <br>
+        Available until November 30.
+      </div>
+
       <button class="btn btn-success" onclick="upgrade({{ PADDLE_MONTHLY_PRODUCT_ID }})">
         Monthly <br>
         $2.99/month