Feature request: Documented Example of Local Authorizer Usage

### Describe your idea/feature/enhancement

@lucashuy love the new feature for local authorizers in 1.80.0+, can we get documentation or a working example of how to set up an authorizer with `sam local start-api`?

### Proposal

Add a sample local_authorizer_template.yml or LOCAL_AUTHORIZER_EXAMPLE.md file that bootstraps the authorizer correctly

Things to consider:
1. Will this require any updates to the [SAM Spec](https://github.com/awslabs/serverless-application-model) - No

### Additional Details

Please provide documentation and examples on how to use a local Authorizer defined within the template.