Updating the helm chart version for stable release (#115)

Issue #, if available: N/A

Description of changes: Let's go GA. Followed instructions here: https://aws-controllers-k8s.github.io/community/docs/contributor-docs/release/#stable-release

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

Author: brycahta

helm/Chart.yaml

@@ -1,7 +1,7 @@
 apiVersion: v1
 name: ec2-chart
 description: A Helm chart for the ACK service controller for Amazon Elastic Cloud Compute (EC2)
-version: v0.0.21
+version: v0-stable
 appVersion: v0.0.21
 home: https://github.com/aws-controllers-k8s/ec2-controller
 icon: https://raw.githubusercontent.com/aws/eks-charts/master/docs/logo/aws.png