Update examples/alerts/alerts.md

Co-authored-by: Matej Gera <38492574+matej-g@users.noreply.github.com>
Signed-off-by: Douglas Camata <159076+douglascamata@users.noreply.github.com>

examples/alerts/alerts.md

@@ -220,7 +220,7 @@ rules:
   annotations:
     description: Thanos Store {{$labels.job}} is failing to handle {{$value | humanize}}% of requests.
     runbook_url: https://github.com/thanos-io/thanos/tree/main/mixin/runbook.md#alert-name-thanosstoregrpcerrorrate
-    summary: Thanos Store is failing to handle grpc requests.
+    summary: Thanos Store is failing to handle gRPC requests.
   expr: |
     (
       sum by (job) (rate(grpc_server_handled_total{grpc_code=~"Unknown|Internal|Unavailable|DataLoss|DeadlineExceeded", job=~".*thanos-store.*"}[5m]))