docs: add CJS/0.x fallback note to README and getting-started

Agent-Logs-Url: https://github.com/albe/node-event-storage/sessions/accacbd4-f01f-40b6-bd9b-9378af17fa42

Co-authored-by: albe <4259532+albe@users.noreply.github.com>

Author: Copilot

README.md

@@ -32,7 +32,9 @@ There is currently only a single other embedded event store for node/javascript:
 npm install event-storage
 ```
 
-## Quick Start
+> **CommonJS / `require()` users:** version 1.0 is ESM-only. If your project uses `require()` and migrating to ESM is not an option, install the 0.x series (`npm install event-storage@0`) which is functionally equivalent and retains full CJS support.
+
+
 
 ```javascript
 import { EventStore } from 'event-storage';

docs/getting-started.md

@@ -8,7 +8,14 @@ Install the package from npm:
 npm install event-storage
 ```
 
-## Quick Start
+!!! note "CommonJS users"
+    Version 1.0 is ESM-only (`import` syntax). If your project uses `require()` and migrating to ESM is not currently an option, the **0.x series** is functionally equivalent and retains full CJS support:
+
+    ```bash
+    npm install event-storage@0
+    ```
+
+
 
 ```javascript
 import { EventStore } from 'event-storage';