Add workflow to publish GitHub release to Modrinth

.github/workflows/publish-modrinth.yml

@@ -0,0 +1,40 @@
+name: Publish to Modrinth
+
+on:
+  release:
+    types: [published]
+
+permissions:
+  contents: read
+
+jobs:
+  publish:
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+
+      - name: Set up JDK 21
+        uses: actions/setup-java@v4
+        with:
+          java-version: '21'
+          distribution: 'temurin'
+
+      - name: Build with Gradle
+        run: ./gradlew build
+
+      - name: Publish to Modrinth
+        uses: cloudnode-pro/modrinth-publish@v2
+        with:
+          token: ${{ secrets.MODRINTH_TOKEN }}
+          project: ${{ vars.MODRINTH_PROJECT_ID }}
+          version: ${{ github.event.release.tag_name }}
+          changelog: ${{ github.event.release.body }}
+          loaders: |-
+            velocity
+            bungeecord
+          game-versions: ">=1.8"
+          files: build/libs/*.jar