Add venv hint to readme

README.md

@@ -17,3 +17,15 @@ Change items in the config section of the script.
 
 Install all dependencies via `python -m pip install -r requirements.txt` and
 use python3 to execute the script.
+
+### How to use with venv
+To keep your local system clean, it might be helpful to store all Python dependencies in one folder.
+Python provides a virtual environment package which can be used to accomplish this task.
+
+```bash
+python3 -m venv migration-env
+source migration-env/bin/activate
+python3 -m pip install -r requirements.txt
+```
+
+Then start the migration script `python3 migrate.py`.