[TASK] Add CI with GitHub actions

.github/workflows/documentation.yml

@@ -0,0 +1,17 @@
+name: test documentation
+
+on: [ push, pull_request ]
+
+jobs:
+  tests:
+    name: documentation
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Test if the documentation will render without warnings
+        run: |
+          mkdir -p Documentation-GENERATED-temp \
+          && docker run --rm --pull always -v $(pwd):/project \
+             ghcr.io/typo3-documentation/render-guides:latest --config=Documentation --no-progress --fail-on-log

.github/workflows/tests.yml

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+name: tests
+
+on:
+  push:
+  pull_request:
+  schedule:
+    # @todo Refactor workflow execution and introduce a generic workflow dispatching
+    # scheduled workflow, so nighlies can be ensured over branches (for the future).
+    - cron: "15 6 * * *"
+
+jobs:
+  lint:
+    name: Linting
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        php:
+          - '8.1'
+          - '8.2'
+          - '8.3'
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Lint PHP
+        run: Build/Scripts/runTests.sh -p ${{ matrix.php }} -s lint
+
+  unit:
+    name: Unit
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        php:
+          - '8.1'
+          - '8.2'
+          - '8.3'
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install testing system
+        run: Build/Scripts/runTests.sh -p ${{ matrix.php }} -s composerUpdate
+
+      - name: unit
+        run: Build/Scripts/runTests.sh -n -p ${{ matrix.php }} -s unit
+
+  functional:
+    name: Functional
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        php:
+          - '8.1'
+          - '8.2'
+          - '8.3'
+        db:
+          - 'mysql'
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install testing system
+        run: Build/Scripts/runTests.sh -p ${{ matrix.php }} -s composerUpdate
+
+      - name: Lint PHP
+        run: Build/Scripts/runTests.sh -p ${{ matrix.php }} -s functional -d ${{ matrix.db }}
+
+  code-quality:
+    name: Code quality
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        php:
+          - '8.1'
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install testing system
+        run: Build/Scripts/runTests.sh -p ${{ matrix.php }} -s composerUpdate
+
+      - name: Composer validate
+        run: Build/Scripts/runTests.sh -p ${{ matrix.php }} -s composerValidate
+
+      - name: Composer normalize
+        run: Build/Scripts/runTests.sh -p ${{ matrix.php }} -s composerNormalize -n
+
+      - name: CGL
+        run: Build/Scripts/runTests.sh -n -p ${{ matrix.php }} -s cgl
+
+      - name: phpstan
+        run: Build/Scripts/runTests.sh -n -p ${{ matrix.php }} -s phpstan