Update documentation around to show that it can be configured as a list to extract roles from nested JWT claims (#10103)

* Update documentation around  to show that it can be configured as a list to extract roles from nested JWT claims

Signed-off-by: Craig Perkins <[email protected]>

* Apply suggestions from code review

Signed-off-by: Naarcha-AWS <[email protected]>

---------

Signed-off-by: Craig Perkins <[email protected]>
Signed-off-by: Naarcha-AWS <[email protected]>
Co-authored-by: Naarcha-AWS <[email protected]>

Author: cwperks

_security/authentication-backends/jwt.md

@@ -121,7 +121,7 @@ Name | Description
 `jwt_header` | The HTTP header in which the token is transmitted. This is typically the `Authorization` header with the `Bearer` schema,`Authorization: Bearer <token>`. Default is `Authorization`. Replacing this field with a value other than `Authorization` prevents the audit log from properly redacting the JWT header from audit messages. It is recommended that users only use  `Authorization` when using JWTs with audit logging. 
 `jwt_url_parameter` | If the token is not transmitted in the HTTP header but rather as an URL parameter, define the name of the parameter here.
 `subject_key` | The key in the JSON payload that stores the username. If not set, the [subject](https://tools.ietf.org/html/rfc7519#section-4.1.2) registered claim is used.
-`roles_key` | The key in the JSON payload that stores the user's roles. The value of this key must be a comma-separated list of roles.
+`roles_key` | The key in the JSON payload that stores the user's roles. The value must be a comma-separated list of roles. You can configure `roles_key` as a list to extract roles from nested JWT claims.
 `required_audience` | The name of the audience that the JWT must specify. You can set a single value (for example, `project1`) or multiple comma-separated values (for example, `project1,admin`). If you set multiple values, the JWT must have at least one required audience. This parameter corresponds to the [`aud` claim of the JWT](https://datatracker.ietf.org/doc/html/rfc7519#section-4.1.3).
 `required_issuer` | The target issuer of JWT stored in the JSON payload. This corresponds to the [`iss` claim of the JWT](https://datatracker.ietf.org/doc/html/rfc7519#section-4.1.1).
 `jwt_clock_skew_tolerance_seconds` | Sets a window of time, in seconds, to compensate for any disparity between the JWT authentication server and OpenSearch node clock times, thereby preventing authentication failures due to the misalignment. Security sets 30 seconds as the default. Use this setting to apply a custom value.

_security/authentication-backends/openid-connect.md

@@ -63,7 +63,7 @@ Name | Description
 `jwt_header` | The HTTP header that stores the token. Typically the `Authorization` header with the `Bearer` schema: `Authorization: Bearer <token>`. Optional. Default is `Authorization`.
 `jwt_url_parameter` | If the token is not transmitted in the HTTP header, but as an URL parameter, define the name of the parameter here. Optional.
 `subject_key` | The key in the JSON payload that stores the user's name. If not defined, the [subject](https://tools.ietf.org/html/rfc7519#section-4.1.2) registered claim is used. Most IdP providers use the `preferred_username` claim. Optional.
-`roles_key` | The key in the JSON payload that stores the user's roles. The value of this key must be a comma-separated list of roles. Required only if you want to use roles in the JWT.
+`roles_key` | The key in the JSON payload that stores the user's roles. The value must be a comma-separated list of roles. This key is required only if you want to use roles in the JWT. You can configure `roles_key` as a list to extract roles from nested JWT claims.
 
 
 ## OpenID Connect URL