title: How to have default MuiTheme file in own Material-UI project
body: <p>I'm building one (own) Material-UI project which I can import whenever I create a new project. So this project only has material-ui and react (react as a peer dependency). I am able to import most of the material-ui components, but <strong>how can I have my own default theme file (Default MuiTheme)?</strong></p>
  
  <p>So, the react project which will import this custom material-ui project and have those default styles from default theme. But, if I want to customize, i should be able to override the mui theme.</p>