[bsb] Tweak react hooks template README (#3974)

Author: chenglou

jscomp/bsb/templates/react-hooks/README.md

@@ -22,8 +22,6 @@ Open a new web page to `http://localhost:8000/`. Change any `.re` file in `src`
 
 **How come we don't need any bundler during development**? We highly encourage you to open up `index.html` to check for yourself!
 
-If you start handling routes via `ReasonReactRouter` change the server script in package.json to `moduleserve ./ --port 8000 --spa` to make sure your routes don't result in a 404 not found error. With the added `--spa` flag your routes will return the index.html on page load and you can handle them client-side.
-
 # Features Used
 
 |                           | Blinking Greeting | Reducer from ReactJS Docs | Fetch Dog Pictures | Reason Using JS Using Reason |
@@ -55,3 +53,9 @@ mv UNUSED_webpack.config.js webpack.config.js
 ./node_modules/.bin/webpack
 open indexProduction.html
 ```
+
+# Handle Routing Yourself
+
+To serve the files, this template uses a minimal dependency called `moduleserve`. A URL such as `localhost:8000/scores/john` resolves to the file `scores/john.html`. If you'd like to override this and handle URL resolution yourself, change the `server` command in `package.json` from `moduleserve ./ --port 8000` to `moduleserve ./ --port 8000 --spa` (for "single page application"). This will make `moduleserve` serve the default `index.html` for any URL. Since `index.html` loads `Index.bs.js`, you can grab hold of the URL in the corresponding `Index.re` and do whatever you want.
+
+By the way, ReasonReact comes with a small [router](https://reasonml.github.io/reason-react/docs/en/router) you might be interested in.