Setup GitHub Actions

Author: DerEchtePilz

.github/workflows/build.yml

@@ -0,0 +1,36 @@
+name: build
+on:
+  push:
+  pull_request:
+    types: [opened, synchronize, reopened]
+
+jobs:
+  build:
+    strategy:
+      matrix:
+        java: [
+          21,
+        ]
+        os: [ubuntu-20.04]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Checkout the docs repository
+        uses: actions/checkout@v3
+
+      - name: Setup JDK ${{ matrix.java }}
+        uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: ${{ matrix.java }}
+          cache: gradle
+
+      - name: Run markdownlint on all documentation Markdown documents
+        uses: DavidAnson/markdownlint-cli2-action@v8
+        with:
+          globs: 'docssrc/src/*.md'
+
+      - name: Build commandapi-documentation-code
+        run: cd commandapi-documentation-code && ./gradlew build
+        
+      - name: Build commandapi-documentation-velocity-code
+        run: cd commandapi-documentation-velocity-code && ./gradlew build