add REST header documentation
*
* A small REST API that uses the HTTP server and JSON serializer to provide
* access to application data for remote applications.
+ *
+ * The endpoints exposed by the REST API are:
+ *
+ * /entity/<path>
+ * The entity endpoint requests data from an entity. The path is the entity
+ * path or name of the entity to query for. The format of the response is
+ * the same as what is returned by ecs_entity_to_json.
+ *
+ * Example:
+ * /entity/my_entity
+ * /entity/parent/child
+ * /entity/420
+ *
+ * /query?q=<query>
+ * The query endpoint requests data for a query. The implementation uses the
+ * rules query engine. The format of the response is the same as what is
+ * returned by ecs_iter_to_json.
+ *
+ * Example:
+ * /query?q=Position
+ * /query?q=Position%2CVelocity
*/
#ifdef FLECS_REST
