Add student discount

apps/client/src/app/pages/pricing/pricing-page.html

@@ -18,7 +18,9 @@
             >contact us</a
           >
           to use our referral link and get a Ghostfolio Premium membership for
-          one year.
+          one year. Looking for a student discount? Request it
+          <a href="mailto:hi@ghostfol.io?Subject=Student Discount">here</a> with
+          your university email address.
         </p>
         <p>
           If you prefer to run Ghostfolio on your own infrastructure, please