Use the Nix in the Github workflow

Author: ibbem

.github/workflows/maven.yml

@@ -15,22 +15,15 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - name: Install Graphviz
-      run: sudo apt-get install -y graphviz
+    - uses: cachix/install-nix-action@v18
     - uses: actions/checkout@v3
-    - name: Set up JDK 17
-      uses: actions/setup-java@v3
-      with:
-        java-version: '17'
-        distribution: 'temurin'
-        cache: maven
-    - name: Build with Maven
-      run: mvn -B --file pom.xml package javadoc:javadoc
+    - name: Build
+      run: nix-build
     - name: Upload Javadoc artifact
       if: ${{ github.event_name == 'push' && github.event.ref == 'refs/heads/main' }}
       uses: actions/upload-pages-artifact@v1
       with:
-        path: docs/javadoc
+        path: result/share/doc/DiffDetective
 
   # An additional job is recommened in the documentation of `actions/deploy-pages`
   deploy-javadoc: