docs: added troubleshooting guide for promise.all (#5586)

* docs: added troubleshooting guide for promise.all

* fix eslint errors

www/apps/docs/content/troubleshooting/promise-all-rollback.md

@@ -0,0 +1,18 @@
+# Database Transaction Not Rolling Back When Promise.all is Used
+
+Due to how `Promise.all` works, when you run multiple database transactions within it, these transactions may not be rolled back when an error occurs.
+
+To mitigate this issue, use the `promiseAll` function which can be imported from `@medusajs/utils`. For example:
+
+```ts
+import { promiseAll } from "@medusajs/utils"
+import { TransactionBaseService } from "@medusajs/medusa"
+
+class MyService extends TransactionBaseService {
+  async performTransactions() {
+    return await promiseAll([
+      // your transactions....
+    ])
+  }
+}
+```