Upload artifact during build (#222)

.github/workflows/maven.yml

@@ -118,6 +118,12 @@ jobs:
       - name: Build this branch
         run: ./mvnw -DskipTests -Dimage.version=CI_ONLY --batch-mode -no-transfer-progress package jib:dockerBuild --file pom.xml
 
+      - name: 'Upload artifact'
+        uses: actions/upload-artifact@v3
+        with:
+          name: planetiler-build
+          path: planetiler-dist/target/*with-deps.jar
+
       - name: Download data (java)
         run: java -jar planetiler-dist/target/*with-deps.jar --only-download --area=monaco