[add] github workflow

.github/workflows/ci.yaml

@@ -0,0 +1,30 @@
+name: Run BaseX Tests
+
+on:
+  pull_request:
+    branches:
+      - main
+  workflow_dispatch: # Enables manual trigger
+  
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+
+    - name: Set up Java
+      uses: actions/setup-java@v2
+      with:
+        java-version: '11'
+        distribution: 'temurin
+
+    - name: Install BaseX
+      run: |
+        wget http://files.basex.org/releases/10.7/BaseX107.zip
+        unzip BaseX107.zip -d basex
+
+    - name: Run BaseX Tests
+      run: |
+        ./basex/bin/basex -t .