An extension to incorporate PortSwigger's Cross-site scripting cheat sheet in to Burp.
Usage is straightforward. Load the extension, browse to or search for the desired payload, then right click or Ctrl+C to copy.
A context menu also provides quick access to recently copied payloads in both normal and URL encoded formats.
Payload data is updated via GitHub when loading the extension (and persisted globally if GitHub is unavailable).
All credit goes to PortSwigger Research and everybody listed here.
Additional thanks to irsdl and CoreyD97.