Added github action

Author: lukasabbe

.github/workflows/build.yml

@@ -0,0 +1,33 @@
+name: build
+on: [push, pull_request]
+
+jobs:
+  build:
+    strategy:
+      matrix:
+        java: [
+          21,
+        ]
+    runs-on: ubuntu-22.04
+    steps:
+      - name: checkout repo
+        uses: actions/checkout@v4
+      - name: validate gradle wrapper
+        uses: gradle/wrapper-validation-action@v2
+      - name: setup jsk ${{ matrix.java }}
+        uses: actions/setup-java@v4
+        with:
+          java-version: ${{ matrix.java }}
+          distribution: 'microsoft'
+      - name: make gradle wrapper executable
+        run: chmod +x ./gradlew
+      - name: build
+        run: ./gradlew build
+      - name: capture build artifacts
+        if: ${{ matrix.java == '21' }}
+        uses: actions/upload-artifact@v4
+        with:
+          name: Artifacts
+          path: |
+            ./fabric/build/libs/
+            ./neoforge/build/libs/