title: Regex repeated words on the same line
body: <p>What is the regular expression to find words that are repeated on the same line?</p>
  <p>I've tried some expressions that I found on Stack Overflow, such as <a href="https://stackoverflow.com/a/213824/1504078">this</a>, but none is working correctly.</p>
  <p>The result I want to achieve:</p>
  <p><img src="https://i.stack.imgur.com/oFTRQ.png" alt="Enter image description here" /></p>