Added better backwards compatibility by reducing the minimum api version to 1.13, and lowering the java build target to 1.8. It is still strongly recommended to use the latest version of Minecraft and Java, as those are what I work and test with.
The world and coordinates of a killed dragon can now be included in the kill reward commands. These can either be in a Spigot or Vanilla format, default as Vanilla so they can be used in execute commands.
Players can now get a reward for killing the dragon or get a random chance based reward for damaging the dragon where the chance is the percent damage done compared to the total damage. Rewards are done through commands using the same placeholders as messages.
More placeholders work in messages now, e.g. the leaderboard can now say "%dmg%/%totaldmg%" to show damage out of total damage.
Added a config option for only sending messages to players in a configured world. This defaults to being disabled, and the world name is the end world by default. An existing config can be deleted to generate a new one or the new values can be added in.
The api-version was dropped to 1.17 to allow the plugin to work on 1.17 servers.