Add GitHub workflow

.github/workflows/gradle.yml

@@ -0,0 +1,26 @@
+# This workflow will build a Java project with Gradle
+# For more information see: https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-gradle
+
+name: Build mod
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+      - uses: actions/setup-java@v3
+        with:
+          distribution: 'temurin'
+          java-version: '8'
+      - name: Grant execute permission for gradlew
+        run: chmod +x gradlew
+      - name: Build the mod
+        run: ./gradlew --no-daemon build
+      - uses: actions/upload-artifact@v2
+        with:
+          name: Package
+          path: build/libs