Add Helm values for local EDOT collector

[sorenlouv]

This PR adds a Helm values file (local-edot.yaml) that configures the OpenTelemetry Demo to send telemetry to a local EDOT collector running on the host machine. This enables a simpler development workflow for Kibana developers who want to test o11y features with Kubernetes-generated telemetry.

1. Start Kibana + ES + edot collector (in Kibana repo)

yarn start
yarn es snapshot --license trial
node scripts/edot_collector.js

2. Start minikube

minikube start --memory=8192 --cpus=4

3. Install OTel demo

helm repo add open-telemetry https://open-telemetry.github.io/opentelemetry-helm-charts
helm upgrade --install otel-demo open-telemetry/opentelemetry-demo \
  --namespace otel-demo --create-namespace \
  -f kubernetes/elastic-helm/demo.yml \
  -f kubernetes/local-edot.yaml \
  --version 0.38.3

4. Port forwarding

kubectl port-forward -n otel-demo svc/frontend-proxy 8080:8080

cc @SrdjanLL

[masci]

I would name the file minikube.yaml because defaults wouldn't work on different local clusters like Kind. Also I would move it under the elastic-helm folder so that all the -f arguments point there for consistency.