SQLite Support

• The plugin now supports SQLite. If you're running a Spigot-only server, you can use SQLite to store nicknames.
  
  For networks (bungeecord / velocity), I recommend using MySQL. This way, nicknames are saved across the network, allowing players to keep their nicknames on all servers.

Extended version support

• The nick plugin (should) now support all versions 1.8 - 1.21

Bugfixing

• Fixed a few bugs and improved the code

NOTE: Please keep in mind that there might still be bugs, especially if you have a lot of plugins on your server. I can't add support for all plugins that exist.
And I also can't guarantee you that it will work on your server.