AWS::Kendra::DataSource SharePointConfiguration - [Coverage] - missing AuthenticationType

### Name of the resource

AWS::Kendra::DataSource

### Resource name

_No response_

### Description

Currently, CloudFormation Resource Type `AWS::Kendra::DataSource` property [SharePointConfiguration](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-kendra-datasource-sharepointconfiguration.html#cfn-kendra-datasource-sharepointconfiguration-sslcertificates3path) does not have the configuration `AuthenticationType` which is supported by the service as we see in the API [SharePointConfiguration](https://docs.aws.amazon.com/kendra/latest/APIReference/API_SharePointConfiguration.html#kendra-Type-SharePointConfiguration-AuthenticationType)

Requesting to add the support for `AuthenticationType` to the CloudFormation Resource Type `AWS::Kendra::DataSource`.

### Other Details

_No response_

Start by comparing the AWS::Kendra::DataSource SharePointConfiguration CloudFormation documentation with the Kendra API SharePointConfiguration reference linked in the issue. Trace how this repository records missing resource coverage and identify the relevant implementation or schema entry point; done means AuthenticationType is supported by the CloudFormation resource and documented consistently.

Written by the indexing model from the issue text.