title: Remove square brackets from string
body: <p>I want to process some text to remove any substrings in square brackets, e.g. converting this:</p>
  
  <blockquote>
    <p>We noted that you failed to attend your [appointment]  last  appointment .
    Our objective is to provide the best service we can for our patients but [we] need patients’ co-operation to do this.  Wasting appointments impedes our ability to see all the patients who need consultations.  [If] you need to cancel an appointment again we would be grateful if you could notify reception in good [time].</p>
  </blockquote>
  
  <p>To this:</p>
  
  <blockquote>
    <p>We noted that you failed to attend your last  appointment .
    Our objective is to provide the best service we can for our patients but need patients’ co-operation to do this.Wasting appointments impedes our ability to see all the patients who need consultations.you need to cancel an appointment again we would be grateful if you could notify reception in good.</p>
  </blockquote>
  
  <p>How can I achieve this?</p>