Add .dockerignore to exclude vendor directory

- Exclude vendor directory from Docker build for now
- This will make the build faster and avoid potential issues
- Will integrate MinerU properly in next iteration

.dockerignore

@@ -0,0 +1,11 @@
+vendor/
+__pycache__/
+*.pyc
+.env
+.venv/
+venv/
+.git/
+.gitignore
+*.log
+test_api_local.py
+output_*.md