Some major features and improvements!
Large config changes were made in this update, so ideally you should delete/rename your current config, restart your server, and copy over any custom settings to the new config. Note some of the new config options' names.

Changelog:

• Added separate config options for defeat announcement of one fight participant and multiple fight participants (#14)
  • Renamed defeat-announcement-message to defeat-announcement-message-one-participant
  • Multiple participants config option is called defeat-announcement-message-multiple-participants
• Added ability to run custom commands upon Dragon death (#6)
  • See the new config for more information
• Added clearer message for when a non-player kills the Dragon (e.g. a bed explosion)
  • When one player is present, they will be presumed to be the killer - otherwise the bed (or other strange damage source) gets credit for being the killer
• Added config versioning, so the plugin will warn you if your config is outdated and might not work
• Rename defeat announcement message config macro <players-in-end> to <participants>
• Fixed trailing commas in list of participants (#13)
• Minor code improvements

As always, if you have any suggestions, bug reports, or other sorts of ideas, please make an issue on GitHub (best option), PM me, or add to the resource discussion.