helm charts for actions runner (#1375)

Fixes: #942 

helm charts for actions runner, currently its having only RunnerDeployment and Autoscaler resources.

Looks like deployment order is important here, facing the below issue if Autoscaler deployed first and then autoscaling not working as expected.
```
2022-04-21T12:13:08Z    DEBUG    controllers.webhookbasedautoscaler    RunnerDeployment not found with scale target ref name test-actions-runner for hra test-actions-runner-autoscaler
```
Helm doesn't support [ordering](https://github.com/helm/helm/issues/8439) for custom resources. So using List to overcome this issue, didn't use helm chart hooks for ordering since its not [tracked](https://helm.sh/docs/topics/charts_hooks/#hook-resources-are-not-managed-with-corresponding-releases) after creation.

Co-authored-by: Josh Feierman <joshua.feierman@warnermedia.com>
Co-authored-by: Yusuke Kuoka <ykuoka@gmail.com>

contrib/examples/actions-runner/values.yaml

@@ -0,0 +1,63 @@
+image:
+  repository: summerwind/actions-runner
+  tag: v2.290.1-ubuntu-20.04
+  pullPolicy: IfNotPresent
+
+# Create runner for an organization or a repository
+# Set only one of the two either organization or repository
+# By default, it creates runner under github organization test
+organization: test
+# repository: mumoshu/actions-runner-controller-ci
+
+# Labels you want to add in your runner
+runnerLabels:
+  - test
+
+# If you enable Autoscaler, then it will not be used
+replicaCount: 1
+
+# The Runner Group that the runner(s) should be associated with.
+# See https://docs.github.com/en/github-ae@latest/actions/hosting-your-own-runners/managing-access-to-self-hosted-runners-using-groups.
+group: Default
+
+autoscaler:
+  enabled: true
+  minReplicas: 1
+  maxReplicas: 5
+  scaleDownDelaySecondsAfterScaleOut: 120
+  # metrics (pull method) / scaleUpTriggers (push method)
+  # https://github.com/actions-runner-controller/actions-runner-controller#pull-driven-scaling
+  # https://github.com/actions-runner-controller/actions-runner-controller#webhook-driven-scaling
+  metrics:
+  - type: PercentageRunnersBusy
+    scaleUpThreshold: '0.75'
+    scaleDownThreshold: '0.25'
+    scaleUpFactor: '2'
+    scaleDownFactor: '0.5'
+  # scaleUpTriggers:
+  # - githubEvent: {}
+  #   duration: "5m"
+
+podAnnotations: {}
+
+podLabels: {}
+
+imagePullSecrets: []
+
+podSecurityContext:
+  {}
+  # fsGroup: 2000
+
+# Leverage a PriorityClass to ensure your pods survive resource shortages
+# ref: https://kubernetes.io/docs/concepts/configuration/pod-priority-preemption/
+# PriorityClass: system-cluster-critical
+priorityClassName: ""
+
+nodeSelector: {}
+
+tolerations: []
+
+affinity: {}
+
+env:
+  {}