Update project configuration and refactor codebase

- Migrated Minestom dependency to new groupId.
- Added Maven Shade plugin for packaging.
- Switched Java version to 21 and corrected JDK settings.
- Refactored terrain generation logic to use the updated Minestom API.
- Replaced deprecated particle creation methods.
- Enabled Velocity proxy support.
- Updated various configuration files to align with the new build setup.

.idea/misc.xml

@@ -8,7 +8,7 @@
       </list>
     </option>
   </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="openjdk-17" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_21" default="true" project-jdk-name="corretto-21" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>