Set version 6.5 and release date in changelog

Merged-by: Martin Grzenia <martin.grzenia@iml.fraunhofer.de>

Author: martingr

opentcs-documentation/src/docs/release-notes/changelog.adoc

@@ -16,15 +16,15 @@ The openTCS developers
 This change log lists the most relevant changes for past releases in reverse chronological order.
 (Note that the openTCS project adheres to https://semver.org/[Semantic Versioning].)
 
-== Unreleased
+== Version 6.5 (2025-08-08)
 
 * New features and enhancements:
 ** Reduce the time it takes to persist large plant models into the kernel.
 ** Avoid re-setting the same processing vehicle of an order sequence, which triggers an entry in the log and one in the sequence's object history.
    And if in some way the same processing vehicle is indeed set again, at least don't add an object history entry.
 ** Add example vehicle envelopes to the demo model.
 ** Update web API specification and implementation to version 1.12.0:
-*** Extend the endpoint `POST /vehicles/NAME/routeComputationQuery` by an optional parameter which specifies the maximum number of routes to compute for one destination point.
+*** Extend the endpoint `POST /vehicles/{NAME}/routeComputationQuery` by an optional parameter which specifies the maximum number of routes to compute for one destination point.
 *** Add an endpoint `POST /vehicles/{NAME}/commAdapter/message`, which allows sending messages to the communication adapter that is attached to a vehicle.
 *** The `GET /events` endpoint now returns status messages of transport orders and vehicles that contain the same information as the transport orders and vehicles returned via the `GET /transportOrders` and `GET /vehicles` endpoints.
 *** Add support for Server-Sent Events (SSE) to the web API.