ci: Add artifact README

Signed-off-by: Minecon724 <git@m724.eu>

.forgejo/workflows/build.yml

@@ -13,8 +13,13 @@ jobs:
       - name: Build
         run: mvn package
 
+      - name: Add build data
+        run: "echo \"$(git describe)\nBuild date: $(date)\n\n$(git log -1)\" > README.txt"
+
       - name: Upload artifacts
         uses: https://github.com/actions/upload-artifact@v3
         with:
-          path: target/blog-*.jar
+          path: |
+            README.txt
+            target/blog-*.jar
           if-no-files-found: error