docs: elaborate on k8s compatibility (#13132)

Signed-off-by: Anton Gilgur <agilgur5@gmail.com>

.spelling

@@ -164,6 +164,7 @@ instantiators
 jenkins
 k3d
 k3s
+k8s
 k8s-jobs
 kube
 kube-apiserver

docs/releases.md

@@ -53,6 +53,10 @@ Otherwise, we typically release every two weeks:
 
 ### Notes on Compatibility
 
-Argo versions may be compatible with newer and older versions than what it is listed but only three minor versions are supported per Argo release unless otherwise noted.
+Argo versions may be compatible with newer and older Kubernetes versions (indicated by `?`), but only three minor versions are tested unless otherwise noted.
 
-The main branch of `Argo Workflows` is currently tested on `Kubernetes` 1.29.
+Note that Kubernetes [is backward compatible with clients](https://github.com/kubernetes/client-go/tree/aa7909e7d7c0661792ba21b9e882f3cd6ad0ce53?tab=readme-ov-file#compatibility-client-go---kubernetes-clusters), so newer k8s versions are generally supported.
+The caveats with newer k8s versions are possible changes to experimental APIs and unused new features.
+Argo uses stable Kubernetes APIs such as Pods and ConfigMaps; see the Controller and Server RBAC of your [installation](installation.md) for a full list.
+
+The `main` branch is currently [tested on Kubernetes 1.26](https://github.com/argoproj/argo-workflows/blob/main/.github/workflows/ci-build.yaml#L218) and [1.29](https://github.com/argoproj/argo-workflows/blob/main/.github/workflows/ci-build.yaml#L250).