Update NPM dependencies

docs/user-manual/editor/launch-page/custom-engine.md

@@ -70,19 +70,19 @@ The Editor only officially supports the current Engine release and the previous
 
 ### Launch with a Locally Built Engine
 
-If you fork the engine repo on GitHub, you can build the engine yourself. To have the launch page launch your custom build, you need to start by serving it from localhost using port 51000. Verify you can see your engine source at the URL:
+If you fork the engine repo on GitHub, you can build the engine yourself (via `npm run build`). To have the launch page launch your custom build, you need to start a local web server by running `npm run serve`.
+
+Verify you can see your engine source at the URL:
 
 ```none
-    http://localhost:51000/path/to/engine/playcanvas-latest.js
+    http://localhost:51000/playcanvas.js
 ```
 
-To now use this engine in the launch page, edit the URL to:
+To use this engine in the launch page, edit the URL to:
 
 ```none
-    http://launch.playcanvas.com/<scene_id>?use_local_engine=http://localhost:51000/path/to/engine/playcanvas-latest.js
+    https://launch.playcanvas.com/<scene_id>?use_local_engine=http://localhost:51000/playcanvas.js
 ```
 
-Note that you must edit the launch page to use http instead of https in order to match the use of http for the locally served engine.
-
 [1]: https://github.com/playcanvas/engine
 [2]: https://github.com/playcanvas/engine/releases