docs: fix typo in integration/prometheus page (#321)

Fixed typo for the podMonitor example under the 'Prometheus community version (helm) - kube-prometheus-stack with pod monitor' section.

Signed-off-by: Desh Deepak Kant <deshdeepakkant@gmail.com>
Signed-off-by: DeshDeepakKant <deshdeepakkant@gmail.com>

Author: DeshDeepakKant

website/docs/integrations/prometheus.md

@@ -174,7 +174,7 @@ spec:
       - litmus
   podMetricsEndpoints:
     - port: tcp
-    - interval: 1s
+      interval: 1s
       metricRelabelings:
         - targetLabel: instance
           replacement: 'chaos-exporter-service'