Initial project setup with Hytale plugin template

Add a minimal, ready-to-use Hytale plugin template including Gradle build scripts, GitHub Actions CI workflow, example plugin class, configuration and manifest files, and supporting documentation. This setup provides modern build tooling, automated server testing, and best practices for plugin development.

.github/workflows/build.yml

@@ -0,0 +1,72 @@
+name: Build Plugin
+
+on:
+  push:
+    branches: [ main, develop ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    
+    steps:
+    - name: Checkout Repository
+      uses: actions/checkout@v4
+    
+    - name: Setup Java 25
+      uses: actions/setup-java@v4
+      with:
+        java-version: '25'
+        distribution: 'temurin'
+    
+    - name: Cache Gradle Dependencies
+      uses: actions/cache@v4
+      with:
+        path: ~/.gradle
+        key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}
+        restore-keys: |
+          ${{ runner.os }}-gradle-
+    
+    - name: Grant Execute Permission for Gradlew
+      run: chmod +x gradlew
+    
+    - name: Build with Gradle
+      run: ./gradlew shadowJar
+    
+    - name: Run Tests
+      run: ./gradlew test
+    
+    - name: Upload Artifact
+      uses: actions/upload-artifact@v4
+      with:
+        name: plugin-jar
+        path: build/libs/*.jar
+        
+  release:
+    needs: build
+    runs-on: ubuntu-latest
+    if: startsWith(github.ref, 'refs/tags/v')
+    
+    steps:
+    - name: Checkout Repository
+      uses: actions/checkout@v4
+    
+    - name: Setup Java 25
+      uses: actions/setup-java@v4
+      with:
+        java-version: '25'
+        distribution: 'temurin'
+    
+    - name: Grant Execute Permission for Gradlew
+      run: chmod +x gradlew
+    
+    - name: Build with Gradle
+      run: ./gradlew shadowJar
+    
+    - name: Create Release
+      uses: softprops/action-gh-release@v1
+      with:
+        files: build/libs/*.jar
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}