Add automatic builds using GitHub Actions

.github/workflows/build.yml

@@ -0,0 +1,63 @@
+name: Build ChatGames
+
+on:
+  push:
+    branches:
+      - master
+      - dev
+    tags:
+      - 'v*'
+  pull_request:
+    branches:
+      - master
+      - dev
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up JDK 21
+        uses: actions/setup-java@v4
+        with:
+          java-version: '21'
+          distribution: 'temurin'
+          cache: 'maven'
+
+      - name: Get version and git hash
+        id: vars
+        run: |
+          VERSION=$(mvn help:evaluate -Dexpression=project.version -q -DforceStdout)
+          SHORT_SHA=$(git rev-parse --short HEAD)
+          echo "version=$VERSION" >> $GITHUB_OUTPUT
+          echo "short_sha=$SHORT_SHA" >> $GITHUB_OUTPUT
+
+      - name: Build with Maven
+        run: mvn clean package --batch-mode --no-transfer-progress
+
+      - name: Collect and rename JARs
+        run: |
+          mkdir -p staging
+          SHORT_SHA=${{ steps.vars.outputs.short_sha }}
+          cp spigot/target/ChatGames-Spigot-*.jar staging/ChatGames-Spigot-${{ steps.vars.outputs.version }}-${SHORT_SHA}.jar
+          cp paper/target/ChatGames-Paper-*.jar staging/ChatGames-Paper-${{ steps.vars.outputs.version }}-${SHORT_SHA}.jar
+          cp folia/target/ChatGames-Folia-*.jar staging/ChatGames-Folia-${{ steps.vars.outputs.version }}-${SHORT_SHA}.jar
+          cp sponge/target/ChatGames-Sponge-*.jar staging/ChatGames-Sponge-${{ steps.vars.outputs.version }}-${SHORT_SHA}.jar
+
+      - name: Upload build artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: ChatGames-${{ steps.vars.outputs.version }}-${{ steps.vars.outputs.short_sha }}
+          path: staging/*.jar
+          if-no-files-found: error
+
+      - name: Create draft release
+        if: startsWith(github.ref, 'refs/tags/')
+        uses: softprops/action-gh-release@v2
+        with:
+          draft: true
+          files: staging/*.jar
+          generate_release_notes: true