Letterboxd Review Formatting par Olle

Adds a formatting toolbar directly to the Letterboxd review text area, so you can apply HTML formatting without typing tags by hand.
Buttons included:
• Bold — wraps selected text in <b>
• Italic — wraps selected text in <i>
• Blockquote — wraps selected text in <blockquote>
• Link — prompts for a URL and wraps selected text in <a href="...">
Simply select text in the review box and click a button. For links, select the display text first, then click the link button and enter a URL when prompted. The toolbar appears automatically whenever you open the review dialog and matches Letterboxd's existing dark UI style.