title: regex replace all backward slashes before '\?'
body: <p>I have a string such as</p>
  
  <pre><code>'frontend\less\defaults\layout.css?file=\foo'
  </code></pre>
  
  <p>I want a regex that replaces it with</p>
  
  <pre><code>'frontend/less/defaults/layout.css?file=\foo'
  </code></pre>
  
  <p>I tried <code>/\\/g</code>, but it keeps matching stuff after a <code>\?</code>, which I want to avoid somehow</p>