Update README.md

README.md

@@ -32,14 +32,14 @@ Upgrading
 Checkout your commit/branch. If you need to reinstall dependencies (you can check [NEWS](NEWS.md)) do the following:
 
 ```
-rm -rf node_modules; npm install
+rm -rf node_modules; yarn
 ```
 
 Run
 ---
 
 ```
-node app.js <env> 
+node app.js <env>
 ```
 
 Where <env> is the name of a configuration file under config/environments/.
@@ -71,12 +71,12 @@ See [CONTRIBUTING.md](CONTRIBUTING.md).
 ### Developing with a custom windshaft version
 
 If you plan or want to use a custom / not released yet version of windshaft (or any other dependency) the best option is
-to use `npm link`. You can read more about it at [npm-link: Symlink a package folder](https://docs.npmjs.com/cli/link).
+to use `yarn link`. You can read more about it at [yarn-link: Symlink a package folder](https://yarnpkg.com/en/docs/cli/link).
 
 **Quick start**:
 
 ```shell
-~/windshaft-directory $ npm install
-~/windshaft-directory $ npm link
-~/windshaft-cartodb-directory $ npm link windshaft
+~/windshaft-directory $ yarn
+~/windshaft-directory $ yarn link
+~/windshaft-cartodb-directory $ yarn link windshaft
 ```