Update docs for v0.13.1 (aws#4522)

EKS Anywhere v0.13.1 Release

Add validation to only support unstacked etcd with static ip for snow (…

…aws#4504)

Removed unused latest minor release e2e test helper methods (aws#4448)

Refactor e2e framework to unify eks-a API updates (aws#4316)

Stop relying on storing the yaml content of the manifest and just use a
cluster.Config. We will follow up with more changes, simplifying how
tests update the cluster config, moving towards using
test.UpdateCLusterConfig. However, this requires changing the interfave
to the framework and hence the tests themselves. We will do that
separately and piece-meal.

Add cluster name to resources defined in clusterresourceset (aws#4249)

Enable full cluster lifecycle controller support (aws#4207)

The controller manager flags will be dynamically set based on the
cluster infra provider and the env var feature flags. This should be
enventually moved to use CRDs for manager config, but that will require
to update the manager setup code as well.

Ensure users download latest version of imagebuilder CLI for building…

… node images (aws#4148)