Update README.md #1

README.md

@@ -136,7 +136,10 @@ export default {
 
 `lean4monaco` contains a sample project `lean4monaco/demo/` which you can use for comparison.
 
-If you cloned `lean4monaco`, you can run the demo with
+Ideally you clone this repo using `git clone --recurse-submodules <ssh/https address>` to load the included submodule.
+(alternatively, call `git submodule init && git submodule update` inside the cloned the repo).
+
+Afterwards, you can run the demo with
 
 ```
 cd lean4monaco
@@ -160,4 +163,4 @@ Some random errors we encountered. If you have more, please share them.
 ### Warnings on `npm install`
 
 * Warnings about `glob` and `inflight` come from `copyfiles`: see [copyfiles#132](https://github.com/calvinmetcalf/copyfiles/pull/132)
-* Warning about ` @types/cypress` comes from `cypress-iframe`
+* Warning about ` @types/cypress` comes from `cypress-iframe`