feat: add new page for self-healing

fix: remove node controller

fix: nit comments

fix: modify replica replacement

Update content/en/docs/concepts/architecture/self-healing.md

Co-authored-by: Tim Bannister <[email protected]>

fix: remove extra line

Author: abhilasha2418

content/en/docs/concepts/architecture/self-healing.md

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+---
+title: Kubernetes Self-Healing  
+content_type: concept  
+Weight: 50  
+---
+<!-- overview -->
+
+Kubernetes is designed with self-healing capabilities that help maintain the health and availability of workloads. 
+It automatically replaces failed containers, reschedules workloads when nodes become unavailable, and ensures that the desired state of the system is maintained.
+
+<!-- body -->
+
+## Self-Healing capabilities {#self-healing-capabilities} 
+
+- **Container-level restarts:** If a container inside a Pod fails, Kubernetes restarts it based on the [`restartPolicy`](/docs/concepts/workloads/pods/pod-lifecycle/#restart-policy)`.
+
+- **Replica replacement:** If a Pod in a [Deployment](/docs/concepts/workloads/controllers/deployment/) or [StatefulSet](/docs/concepts/workloads/controllers/statefulset/) fails, Kubernetes creates a replacement Pod to maintain the specified number of replicas.
+  If a Pod fails that is part of a [DaemonSet](/docs/concepts/workloads/controllers/daemonset/) fails, the control plane
+  creates a replacement Pod to run on the same node.
+  
+- **Persistent storage recovery:** If a node is running a Pod with a PersistentVolume (PV) attached, and the node fails, Kubernetes can reattach the volume to a new Pod on a different node.
+
+- **Load balancing for Services:** If a Pod behind a [Service](/docs/concepts/services-networking/service/) fails, Kubernetes automatically removes it from the Service's endpoints to route traffic only to healthy Pods.
+
+Here are some of the key components that provide Kubernetes self-healing:
+
+- **[kubelet](/docs/concepts/architecture/#kubelet):** Ensures that containers are running, and restarts those that fail.
+
+- **ReplicaSet, StatefulSet and DaemonSet controller:** Maintains the desired number of Pod replicas.
+
+- **PersistentVolume controller:** Manages volume attachment and detachment for stateful workloads.
+
+## Considerations {#considerations} 
+
+- **Storage Failures:** If a persistent volume becomes unavailable, recovery steps may be required.
+
+- **Application Errors:** Kubernetes can restart containers, but underlying application issues must be addressed separately.
+
+## {{% heading "whatsnext" %}} 
+
+- Read more about [Pods](/docs/concepts/workloads/pods/)
+- Learn about [Kubernetes Controllers](/docs/concepts/architecture/controller/)
+- Explore [PersistentVolumes](/docs/concepts/storage/persistent-volumes/)
+- Read about [node autoscaling](/docs/concepts/cluster-administration/node-autoscaling/). Node autoscaling
+  also provides automatic healing if or when nodes fail in your cluster.