title: How to highlight merge conflict blocks in monaco-editor like VSCode?
body: <p>VSCode has a good feature to highlight merge conflict blocks in this way:
  <a href="https://i.stack.imgur.com/Gn6oW.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Gn6oW.png" alt="VSCode merge conflicts"></a></p>
  
  <p>So I wonder how to achieve that in monaco-editor? </p>
  
  <p>I checked the API and found a related one: <code>colorizeModelLine(model: ITextModel, lineNumber: number, tabSize?: number): string</code>.</p>