title: Traefik replacePathRegex understanding
body: <p>I try to understand a Traefik RegEx rule for replace.
  The RegEx is:</p>
  <pre><code>regex: ^/([^/]*)/(.*)
  replacement: /$2
  </code></pre>
  <p>The path variable is <code>/api</code></p>
  <p>As far as I understand is:</p>
  <pre><code>$1 = Domain &lt;^/&gt;
  $2 = path &lt;([^/]*)&gt;
  $3 = file &lt;/(.*)&gt;
  </code></pre>
  <p>So for <code>/api</code> it is:</p>
  <ul>
  <li>my.com/api/test.html =&gt; my.com/api/test.html</li>
  <li>my.com/api/block2/test.html =&gt; my.com/api/test.html</li>
  <li>my.com/block1/test.html =&gt; my.com/api/test.html</li>
  <li>my.com/test.html =&gt; my.com/test.html</li>
  </ul>
  <p>Is this the right way or do I missundertand something?</p>