text: Title: CSS/JS console and ipython fix
  Body: Some of our code snippets display as a terminal (i.e., the line starts with a  `$`), or an IPython prompt (i.e., line starts with `In []:`). See this: https://ploomber.readthedocs.io/en/latest/user-guide/scaffold.html
  
  The corresponding CSS is here: https://github.com/ploomber/ploomber/blob/fd9b4c7a2e787c0206f841928d1be90ac142c7a8/doc/_static/css/custom-theme.css#L83
  
  However, this only works when the terminal only displays one line, if there are more lines, it doesn't work:
  
  ```sh
  $ some command
  another_command # this one doesn't have the $
  ```
  
  Not sure if we can fix this purely with CSS or we need some JS.
  
  