Fix grammar, formatting, and a command on EKS add-on page (#44385)

Signed-off-by: David Xia <[email protected]>

Author: davidxia

website/docs/r/eks_addon.html.markdown

@@ -38,13 +38,14 @@ Custom add-on configuration can be passed using `configuration_values` as a sing
 
 ~> **Note:** `configuration_values` is a single JSON string should match the valid JSON schema for each add-on with specific version.
 
-To find the correct JSON schema for each add-on can be extracted using [describe-addon-configuration](https://docs.aws.amazon.com/cli/latest/reference/eks/describe-addon-configuration.html) call.
-This below is an example for extracting the `configuration_values` schema for `coredns`.
+You can use [describe-addon-configuration](https://docs.aws.amazon.com/cli/latest/reference/eks/describe-addon-configuration.html) to extract each add-on's JSON schema.
+Here's an example command to extract the `configuration_values` schema for `coredns`.
 
 ```bash
- aws eks describe-addon-configuration \
- --addon-name coredns \
- --addon-version v1.10.1-eksbuild.1
+aws eks describe-addon-configuration \
+  --addon-name coredns \
+  --addon-version v1.10.1-eksbuild.1 \
+  | jq -r .configurationSchema | jq .
 ```
 
 Example to create a `coredns` managed addon with custom `configuration_values`.