nicko

[FEATURES]

• Updated to support Minecraft 1.21.5.
• Added a sub-command (/nicko about) to get information about Nicko.
• Modernized the messages and added various sound effects upon interacting with the plugin.
• Cleaned up GUI titles.

[FIXES]

• Fixed an oversight preventing the configuration from properly being migrated.
• Fixed a rare bug that could prevent data from being saved.
• Fixed the placeholder item in the skin cache invalidation not being translated.
• Fixed a oversight about a column name using SQL storage.

[LANGUAGE]

• Moved the prefix to the language file.

[OTHER]

• Cleaned up the codebase to prepare for future updates.