[Docs] Add an inline kubeconfig example to the kubernetes backend documentation

docs/blog/posts/gpu-health-checks.md

@@ -68,6 +68,6 @@ If you have experience with GPU reliability or ideas for automated recovery, joi
 
 !!! info "What's next?"
     1. Check [Quickstart](../../docs/quickstart.md)
-    2. Explore the [clusters](../../docs/guides/clusters.md) guide
+    2. Explore the [clusters](../../examples.md#clusters) examples
     3. Learn more about [metrics](../../docs/concepts/metrics.md)
     4. Join [Discord](https://discord.gg/u8SmfwPpMd)

docs/blog/posts/kubernetes-beta.md

@@ -311,5 +311,5 @@ Support for AMD GPUs is coming soon — our team is actively working on it right
     2. Explore [dev environments](../../docs/concepts/dev-environments.md), 
         [tasks](../../docs/concepts/tasks.md), [services](../../docs/concepts/services.md), 
         and [fleets](../../docs/concepts/fleets.md)
-    3. Read the the [clusters](../../docs/guides/clusters.md) guide
+    3. Browse the [clusters](../../examples.md#clusters) examples
     4. Join [Discord](https://discord.gg/u8SmfwPpMd)

docs/blog/posts/nebius-in-dstack-sky.md

@@ -104,7 +104,7 @@ $ dstack apply -f my-cluster.dstack.yml
 Once the fleet is ready, you can run [distributed tasks](../../docs/concepts/tasks.md#distributed-tasks). 
 `dstack` automatically configures drivers, networking, and fast GPU-to-GPU interconnect.
 
-To learn more, see the [clusters](../../docs/guides/clusters.md) guide.
+To learn more, see the [clusters](../../examples/clusters/nebius/index.md) guide.
 
 With Nebius joining `dstack` Sky, users can now run on-demand and spot GPUs and clusters directly through the marketplace—gaining access to the same production grade infrastrucure Nebius customers use for frontier-scale training, without needing a separate Nebius account. 
 
@@ -124,4 +124,4 @@ Our goal is to give teams maximum flexibility while removing the complexity of m
     4. Explore [dev environments](../../docs/concepts/dev-environments.md), 
         [tasks](../../docs/concepts/tasks.md), [services](../../docs/concepts/services.md), 
         and [fleets](../../docs/concepts/fleets.md)
-    5. Reaad the the [clusters](../../docs/guides/clusters.md) guide
+    5. Read the [clusters](../../examples/clusters/nebius/index.md) guide

docs/docs/concepts/backends.md

@@ -464,7 +464,7 @@ There are two ways to configure GCP: using a service account or using the defaul
     </div>
 
     ??? info "User interface"
-        If you are configuring the `gcp` backend on the [project settigns page](projects.md#backends), 
+        If you are configuring the `gcp` backend on the [project settings page](projects.md#backends),
         specify the contents of the JSON file in `data`:
 
         <div editor-title="~/.dstack/server/config.yml">
@@ -699,7 +699,7 @@ projects:
     ```
 
 ??? info "User interface"
-    If you are configuring the `nebius` backend on the [project settigns page](projects.md#backends), 
+    If you are configuring the `nebius` backend on the [project settings page](projects.md#backends),
     specify the contents of the private key file in `private_key_content`:
 
     <div editor-title="~/.dstack/server/config.yml">
@@ -1048,16 +1048,18 @@ projects:
 - name: main
   backends:
   - type: kubernetes
+
     kubeconfig:
       filename: ~/.kube/config
+
     proxy_jump:
       hostname: 204.12.171.137
       port: 32000
 ```
 
 </div>
 
-??? info "Proxy jump"
+!!! info "Proxy jump"
     To allow the `dstack` server and CLI to access runs via SSH, `dstack` requires a node that acts as a jump host to proxy SSH traffic into containers.  
 
     To configure this node, specify `hostname` and `port` under the `proxy_jump` property:  
@@ -1067,6 +1069,46 @@ projects:
 
     No additional setup is required — `dstack` configures and manages the proxy automatically.
 
+??? info "User interface"
+    If you are configuring the `kubernetes` backend on the [project settings page](projects.md#backends),
+    specify the contents of the `kubeconfig` file in `data`:
+
+    <div editor-title="~/.dstack/server/config.yml">
+
+    ```yaml
+    type: kubernetes
+
+    kubeconfig:
+      data: |
+        apiVersion: v1
+        kind: Config
+        current-context: kubernetes-admin@gpu-cluster
+
+        clusters:
+        - name: gpu-cluster
+          cluster:
+            server: https://gpu-cluster.internal.example.com:6443
+            certificate-authority-data: LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0t...LS0tLQo=
+
+        users:
+        - name: kubernetes-admin
+          user:
+            client-certificate-data: LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0t...LS0tLQo=
+            client-key-data: LS0tLS1CRUdJTiBQUklWQVRFIEtFWS0tLS0t...LS0tLQo=
+
+        contexts:
+        - name: kubernetes-admin@gpu-cluster
+          context:
+            cluster: gpu-cluster
+            user: kubernetes-admin
+
+    proxy_jump:
+      hostname: 204.12.171.137
+      port: 32000
+    ```
+
+    </div>
+
 ??? info "Required operators"
     === "NVIDIA"
         For `dstack` to correctly detect GPUs in your Kubernetes cluster, the cluster must have the