Promote sysctls to Beta (#8804)

* Promote sysctls to Beta

* Copyedits

Signed-off-by: Misty Stanley-Jones <mistyhacks@google.com>

* Review comments

* Address feedback

* More feedback

content/en/docs/reference/command-line-tools-reference/feature-gates.md

@@ -89,6 +89,7 @@ different Kubernetes components.
 | `SupportIPVSProxyMode` | `true` | Beta | 1.10 | 1.10 |
 | `SupportIPVSProxyMode` | `true` | GA | 1.11 | |
 | `SupportPodPidsLimit` | `false` | Alpha | 1.10 | |
+| `Sysctls` | `true` | Beta | 1.11 | |
 | `TaintBasedEvictions` | `false` | Alpha | 1.6 | |
 | `TaintNodesByCondition` | `false` | Alpha | 1.8 | |
 | `TokenRequest` | `false` | Alpha | 1.10 | |
@@ -216,6 +217,8 @@ Each feature gate is designed for enabling/disabling a specific feature:
 - `SupportIPVSProxyMode`: Enable providing in-cluster service load balancing using IPVS.
   See [service proxies](/docs/concepts/services-networking/service/#virtual-ips-and-service-proxies) for more details.
 - `SupportPodPidsLimit`: Enable the support to limiting PIDs in Pods.
+- `Sysctls`: Enable support for namespaced kernel parameters (sysctls) that can be set for each pod.
+  See [sysctls](/docs/tasks/administer-cluster/sysctl-cluster/) for more details.
 - `TaintBasedEvictions`: Enable evicting pods from nodes based on taints on nodes and tolerations on Pods.
   See [taints and tolerations](/docs/concepts/configuration/taint-and-toleration/) for more details.
 - `TaintNodesByCondition`: Enable automatic tainting nodes based on [node conditions](/docs/concepts/architecture/nodes/#condition).
@@ -224,4 +227,3 @@ Each feature gate is designed for enabling/disabling a specific feature:
   PersistentVolumeClaim (PVC) binding aware of scheduling decisions. It also
   enables the usage of [`local`](/docs/concepts/storage/volumes/#local) volume
   type when used together with the `PersistentLocalVolumes` feature gate.
-