[documentation] Outdated "typical usage" example in examples/README.md for z_put.py

[phantom-duck]

Describe the bug

In the following part of examples/README.md, the suggested command is not up to date, the syntax has changed.

zenoh-python/examples/README.md

Lines 51 to 53 in 6d4a264

	```bash
	python3 z_put.py -k demo/example/test -v 'Hello World'
	```

To reproduce

1. Clone repo
2. cd into examples/
3. Run python3 z_put.py -k demo/example/test -v 'Hello World', as suggested in the README
4. Command fails with error: unrecognized arguments

System info

• Platform: Ubuntu 20.04 LTS (Focal Fossa)
• CPU: Intel Core i9-13900K
• Zenoh version: 1.0.0, according to pip list