Add Code blocks in configure-service-account.md

* Add Code blocks in the Markdown spec to make it easy to read.

* Uniform case and adjustment description for smoother writing.

Signed-off-by: ydFu <ader.ydfu@gmail.com>

content/en/docs/tasks/configure-pod-container/configure-service-account.md

@@ -82,6 +82,7 @@ You can list this and any other serviceAccount resources in the namespace with t
 ```shell
 kubectl get serviceaccounts
 ```
+
 The output is similar to this:
 
 ```
@@ -108,9 +109,10 @@ If you get a complete dump of the service account object, like this:
 ```shell
 kubectl get serviceaccounts/build-robot -o yaml
 ```
+
 The output is similar to this:
 
-```
+```yaml
 apiVersion: v1
 kind: ServiceAccount
 metadata:
@@ -164,6 +166,7 @@ Any tokens for non-existent service accounts will be cleaned up by the token con
 ```shell
 kubectl describe secrets/build-robot-secret
 ```
+
 The output is similar to this:
 
 ```
@@ -227,7 +230,7 @@ kubectl get serviceaccounts default -o yaml > ./sa.yaml
 
 The output of the `sa.yaml` file is similar to this:
 
-```shell
+```yaml
 apiVersion: v1
 kind: ServiceAccount
 metadata:
@@ -244,7 +247,7 @@ Using your editor of choice (for example `vi`), open the `sa.yaml` file, delete
 
 The output of the `sa.yaml` file is similar to this:
 
-```shell
+```yaml
 apiVersion: v1
 kind: ServiceAccount
 metadata:
@@ -319,7 +322,8 @@ kubectl create -f https://k8s.io/examples/pods/pod-projected-svc-token.yaml
 ```
 
 The kubelet will request and store the token on behalf of the pod, make the
-token available to the pod at a configurable file path, and refresh the token as it approaches expiration. Kubelet proactively rotates the token if it is older than 80% of its total TTL, or if the token is older than 24 hours.
+token available to the pod at a configurable file path, and refresh the token as it approaches expiration.
+The kubelet proactively rotates the token if it is older than 80% of its total TTL, or if the token is older than 24 hours.
 
 The application is responsible for reloading the token when it rotates. Periodic reloading (e.g. once every 5 minutes) is sufficient for most use cases.
 
@@ -380,7 +384,6 @@ JWKS URI is required to use the `https` scheme.
 
 ## {{% heading "whatsnext" %}}
 
-
 See also:
 
 - [Cluster Admin Guide to Service Accounts](/docs/reference/access-authn-authz/service-accounts-admin/)