feat: Configure production deployment with math-tables namespace and ingress

Changes made:

- Remove problematic configuration-snippet from base ingress

- Add namespace creation for math-tables

- Configure ingress with nginx class and letsencrypt-prod issuer

- Set production hostname to math-tables.cl1.parano.ch

- Reduce production replicas to 1

- Update copyright year in index.html

deploy/base/pod-disruption-budget.yaml

@@ -0,0 +1,9 @@
+apiVersion: policy/v1
+kind: PodDisruptionBudget
+metadata:
+  name: math-exercises-pdb
+spec:
+  minAvailable: 1
+  selector:
+    matchLabels:
+      app: math-exercises