chore: fix payloads of events in TSDocs + description of emitEventStep (medusajs#14132)

Author: shahednasser

packages/core/core-flows/src/common/steps/emit-event.ts

@@ -30,6 +30,8 @@ type Input = {
    * The data payload that the subscriber receives in the `data` property
    * of its first parameter. Use this property to pass data relevant for the
    * subscriber, such as the ID of a created record.
+   * 
+   * If you pass an array of objects, the event will be emitted once per each object in the array.
    */
   data:
     | ((context: StepExecutionContext) => Promise<Record<any, any>>)
@@ -46,12 +48,30 @@ export const emitEventStepId = "emit-event-step"
  * If the workflow fails, it won't emit the event at all.
  *
  * @example
+ * To emit a single event with a data payload:
+ * 
+ * ```ts
  * emitEventStep({
  *   eventName: "custom.created",
  *   data: {
  *     id: "123"
  *   }
  * })
+ * ```
+ * 
+ * To emit an event multiple times with different data payloads, pass an array of objects to the `data` property:
+ * 
+ * ```ts
+ * emitEventStep({
+ *   eventName: "custom.created",
+ *   data: [
+ *     // emit will be emitted three times, once per each object in the array
+ *     { id: "123" },
+ *     { id: "456" },
+ *     { id: "789" }
+ *   ]
+ * })
+ * ```
  */
 export const emitEventStep = createStep(
   emitEventStepId,