Added a GitHub Action to compile JChemPaint

.github/workflows/maven.yml

@@ -0,0 +1,30 @@
+name: build
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        java: [ 8, 11 ]
+    name: Java ${{ matrix.java }}
+
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up Java
+      uses: actions/setup-java@v4
+      with:
+        distribution: 'temurin'
+        java-version: ${{ matrix.java }}
+        cache: maven
+    - name: Build with Maven
+      run: mvn clean install -q