lesson definition <lessons> file, lesson.meta.yaml, which can be found at the root of any lesson directory. Within this file, Endpoints are declared under the endpoints key, like so:name field is up to you to define - you can call each endpoint whatever you want, provided all endpointsimage field is a DockerHub-compatible image reference, which is passed directly to the underlying Kubernetes infrastructure to run your image. See here for more information on images.configurationType field is optional, and allows you to specify what kind of automaticpresentations field is also optional, and allows you to specify ways that this endpoint should be presented to the user. This could be a CLI terminal, or even a web application with it's own tab. See here for more information on endpoint presentations.additionalPorts field allows you to specify any additional ports that should be opened for this endpoint. By default, only the ports listed in a presentation are opened. So, this field allows you to directly specify ports that should be opened regardless of the presentations that are configured.presentations field. By default, for every Presentation, Syringe will perform a basic TCP connection periodically as a heartbeat to ensure that these presentations are accessible. This means that each endpoint must be able to provide connectivity on every port opened by a Presentation.additionalPorts field is required, and must have at least one port configured. Syringe will then use the first port in this list to perform a health check, and will mark the endpoint as healthy.