add receipt page for plan

cmd/web/templates/receipt-plan.page.gohtml

@@ -0,0 +1,24 @@
+{{ template "base" . }}
+{{ define "title" }}
+Payment Succedded!
+{{ end }}
+{{ define "content" }}
+{{$txn := index .Data "txn"}}
+<h2 class="mt-5">Payment Succeeded</h2>
+<hr>
+<p>Customer Name: <span id="first-name"></span> <span id="last-name"></span></p>
+<p>Payment Amount: <span id="amount"></span></p>
+<p>Last Four: <span id="last-four"></span></p>
+{{ end }}
+
+{{define "js"}}
+<script>
+if (sessionStorage.first_name) {
+    document.getElementById("first-name").innerHTML = sessionStorage.first_name;
+    document.getElementById("last-name").innerHTML = sessionStorage.last_name;
+    document.getElementById("amount").innerHTML = sessionStorage.amount;
+    document.getElementById("last-four").innerHTML = sessionStorage.last_four;
+    sessionStorage.clear();
+}
+</script>
+{{end}}