title: Remove part of String in JavaScript
body: <p>I have a String like </p>
  
  <pre><code>var str = "test\ntesttest\ntest\nstringtest\n..."
  </code></pre>
  
  <p>If I reached a configured count of lines ('\n') in the string, I want to remove the first line. That means all text to the first '\n'. </p>
  
  <p>Before:</p>
  
  <pre><code>var str = "test1\ntesttest2\ntest3\nstringtest4\n...5"
  </code></pre>
  
  <p>After:</p>
  
  <pre><code>var str = "testtest2\ntest3\nstringtest4\n...5"
  </code></pre>
  
  <p>Is there a function in Javascript that I can use?</p>
  
  <p>Thanks for help!</p>