Merge pull request #2921 from vector-im/dbkr/update_readme_for_js_sdk_transpiled

Update README now the js-sdk has a transpile step

README.md

@@ -57,9 +57,13 @@ to build.
 1. Switch to the vector-web directory: `cd vector-web`
 1. Install the prerequisites: `npm install`
 1. If you are using the `develop` branch of vector-web, you will probably need
-   to rebuild one of the dependencies, due to
-   https://github.com/npm/npm/issues/3055: `(cd node_modules/matrix-react-sdk
-   && npm install)`
+   to rebuild some of the dependencies, due to
+   https://github.com/npm/npm/issues/3055:
+
+   ```
+   (cd node_modules/matrix-js-sdk && npm install)
+   (cd node_modules/matrix-react-sdk && npm install)
+   ```
 1. Configure the app by copying `config.sample.json` to `config.json` and
    modifying it (see below for details)
 1. `npm run dist` to build a tarball to deploy. Untaring this file will give
@@ -241,10 +245,10 @@ Finally, build and start Riot itself:
    disables caching, so do NOT use it in production.
 1. Open http://127.0.0.1:8080/ in your browser to see your newly built Riot.
 
-When you make changes to `matrix-react-sdk`, you will need to run `npm run
-build` in the relevant directory. You can do this automatically by instead
-running `npm start` in the directory, to start a development builder which
-will watch for changes to the files and rebuild automatically.
+When you make changes to `matrix-react-sdk` or `matrix-js-sdk`, you will need
+to run `npm run build` in the relevant directory. You can do this automatically
+by instead running `npm start` in the directory, to start a development builder
+which will watch for changes to the files and rebuild automatically.
 
 If you add or remove any components from the Riot skin, you will need to rebuild
 the skin's index by running, `npm run reskindex`.