[SERV-908] Reduce cleverness of import-items setup instructions (#55)

* Add PATH env var recommendation

src/main/scripts/import-items/README.md

@@ -9,9 +9,23 @@ Tested with Python 3.6.9.
 ```bash
 #!/bin/bash
 
-python3 -m venv venv_import_items && . $_/bin/activate
-# (exit virtual environment later with `deactivate`)
+# Create a virtual environment to isolate the system Python installation from the script dependencies that we'll download
+python3 -m venv venv_import_items
+
+# Activate the virtual environment; deactivate it later by running `deactivate`
+. venv_import_items/bin/activate
+
+# Install the script dependencies to the virtual environment
 pip install -r requirements.txt
+
+# Ensure the script is executable
+chmod +x import-items.py
+```
+
+Also, you may want to add something like this to your shell's initialization file (e.g. `~/.zshrc`), so that you can easily reference the script from anywhere:
+
+```bash
+PATH=$PATH:$HOME/path/to/UCLALibrary/hauth/src/main/scripts/import-items
 ```
 
 ## Example usage