Updated 'Setting up a dev environment' in README.md (#21597)

README.md

@@ -305,11 +305,19 @@ yarn install
 popd
 ```
 
-Finally, build and start Element itself:
+Clone the repo and switch to the `element-web` directory:
 
 ```bash
 git clone https://github.com/vector-im/element-web.git
 cd element-web
+```
+
+Configure the app by copying `config.sample.json` to `config.json` and
+modifying it. See the [configuration docs](docs/config.md) for details.
+
+Finally, build and start Element itself:
+
+```bash
 yarn link matrix-js-sdk
 yarn link matrix-react-sdk
 yarn install
@@ -330,9 +338,6 @@ Wait a few seconds for the initial build to finish; you should see something lik
    and rebuilds source files when they change. This development server also
    disables caching, so do NOT use it in production.
 
-Configure the app by copying `config.sample.json` to `config.json` and
-modifying it. See the [configuration docs](docs/config.md) for details.
-
 Open <http://127.0.0.1:8080/> in your browser to see your newly built Element.
 
 **Note**: The build script uses inotify by default on Linux to monitor directories