Updating docs around v3 and v4

The README and contributing document now directly address Helm
v4 and v3 to direct contributors.

Signed-off-by: Matt Farina <matt@mattfarina.com>

CONTRIBUTING.md

@@ -11,6 +11,10 @@ vulnerability_, please email a report to
 [cncf-helm-security@lists.cncf.io](mailto:cncf-helm-security@lists.cncf.io). This will give us a
 chance to try to fix the issue before it is exploited in the wild.
 
+## Helm v3 and v4
+
+Helm v4 is currently under development on the `main` branch. During the development of Helm v4 and for some time after its released, Helm v3 will continue to be supported and developed on the `dev-v3` branch. Helm v3 will continue to get bug fixes and updates for new Kubernetes releases. Helm v4 is where new features and major changes will happen. For features to be backported to Helm v3, an exception will be needed. Bugs should first be fixed on Helm v4 and then backported to Helm v3.
+
 ## Sign Your Work
 
 The sign-off is a simple line at the end of the explanation for a commit. All commits need to be

README.md

@@ -56,6 +56,8 @@ Get started with the [Quick Start guide](https://helm.sh/docs/intro/quickstart/)
 
 The [Helm roadmap uses GitHub milestones](https://github.com/helm/helm/milestones) to track the progress of the project.
 
+The development of Helm v4 is currently happening on the `main` branch while the development of Helm v3, the stable branch, is happening on the `dev-v3` branch. Changes should be made to the `main` branch prior to being added to the `dev-v3` branch so that all changes are carried along to Helm v4.
+
 ## Community, discussion, contribution, and support
 
 You can reach the Helm community and developers via the following channels: