title: Add additional/custom props to Material UI
body: <p>I would like to know if it is possible to add custom props to a Material UI component. In other words, I would like to have additional props to the one provided by the API for a given component.</p>
  <p>Example using <code>Link</code>: <a href="https://material-ui.com/api/link/" rel="nofollow noreferrer">https://material-ui.com/api/link/</a></p>
  <p>From the documentation, Link does not have a props <code>active</code>, I would like to add it.</p>
  <p>Codesandbox: <a href="https://codesandbox.io/s/interesting-robinson-2zfw4?file=/src/App.tsx" rel="nofollow noreferrer">https://codesandbox.io/s/interesting-robinson-2zfw4?file=/src/App.tsx</a></p>
  <p>What I tried:</p>
  <pre><code>import React from 'react'
  import { WithStyles, withStyles } from '@material-ui/core/styles'
  import Link from '@material-ui/core/Link'
  
  interface OwnProps extends WithStyles&lt;typeof styles&gt; {
    active?: boolean
  }
  
  export type Props = OwnProps &amp; React.InputHTMLAttributes&lt;HTMLInputElement&gt; &lt;-- I tried also &quot;&amp; any&quot;
  
  const MyCustomLink: React.FC&lt;Props&gt; = (props: Props) =&gt; {
    const { active }: Props = props
  
    return &lt;Link active={active} &gt; My link &lt;/Link&gt;
  }
  
  export default withStyles(styles)(MyCustomLink)
  </code></pre>
  <p>I was thinking that by passing <code>active</code> in my <code>OwnProps</code> and this to <code>Pros</code>, then also the <code>MyCustomLink</code> component would have the <code>active</code> props.
  I am wrong.</p>
  <p>The error I get is:</p>
  <blockquote>
  <p>Property 'active' does not exist on type 'IntrinsicAttributes &amp; AnchorHTMLAttributes</p>
  </blockquote>