title: How to install all the dependency package in yarn?
body: <p>First, I'm new to React. I'm trying to use Google's <code>Material-UI</code> for my React project. In <a href="https://demos.creative-tim.com/material-kit-react/?_ga=2.235048965.509906277.1536193012-1441586403.1534889788#/documentation/tutorial" rel="noreferrer">this tutorial</a>, it says run <code>npm install</code>, but I heard using <code>yarn</code> and <code>npm</code> together in the same project because it might bring about some confusion between those two later. So, I'm trying to stick to <code>yarn</code> only. </p>
  
  <p><code>npm install</code> seems to install all the dependency package for the thing that I wanna use, but how can I do that in yarn? I tried <code>yarn add</code>, but it didn't work. How can I do that?</p>
  
  <p><strong>EDIT</strong></p>
  
  <p>Just found that it has only <code>package.json</code>, which means I can only use <code>npm install</code> to install dependencies. Would there be no problem when I use yarn later?</p>