If the default line spacing of the Text widget is double-line spacing, you can hit the Shift-Enter keys together (Firefox and Internet Explorer) or Ctrl-Enter (Safari) when you want to go to the next single line.
If you wish to have more control over the line spacing, consider using the Style Designer.
- Go to Style > Designer.
- In the "Font" section, click Paragraph Text.
- Click Line Height.
- A slider bar will appear. Move the slider bar to increase or decrease your line spacing. You can also input a number (e.g. 2).
- Click Save to apply the changes to your site.