docs: add warning about keeping indexer version aligned with project …

…version (#1494)

Co-authored-by: alvarius <[email protected]>

docs/pages/indexer.mdx

@@ -28,6 +28,14 @@ They are written under the assumption you are using `anvil` for your test chain,
 1. Run a test world.
    The easiest way to do this is to follow [these directions](tutorials/minimal#getting-the-initial-version) in a separate command line window.
 
+   **Note**: While MUD v2 is in alpha, there might be breaking changes between pre-release versions.
+   To ensure your World is compatible with your indexer, make sure both are running the same MUD version.
+   To create a project with the MUD version on the `main` branch, use `mud@main` instead of ~`mud@next`~.
+
+   ```sh copy
+   pnpm create mud@main project-name
+   ```
+
 1. Start the indexer.
 
    ```sh copy