title: set background color for specific cell in markdown table
body: <p>I have a markdown table as below:</p>
  
  <pre><code>| 1 | 2 | 3 |
  |---|---|---|
  | 4 | 5 | 6 |
  | 7 | 8 | 9 |
  </code></pre>
  
  <p>I wish to set background color to red for a specific cell, e.g. cell 8. I found some forum discussed to use HTML syntax to set font color but not found anyone can set the whole cell background color to red.</p>