readme: Remove need for Poetry to run examples

Still a discovery process which does and shall
not requires Poetry, unless editing the examples

Try to simplify the entry

Remove Poetry installation for the usage, discovery
not DuniterPy development itself

README.md

@@ -58,10 +58,6 @@ pip install --user duniterpy
 Once you want to add DuniterPy to your Python project, you can add it as a dependency to your Python development environment: `pyproject.toml`, `requirements.txt`, `setup.py`.
 We recommend [Poetry](https://python-poetry.org) usage.
 
-## Install the development environment
-
-- [Install Poetry](https://python-poetry.org/docs/#installation)
-
 ## Documentation
 
 [Online official automaticaly generated documentation](https://clients.pages.duniter.org/python/duniterpy/index.html)
@@ -74,15 +70,17 @@ The [examples folder](https://git.duniter.org/clients/python/duniterpy/tree/mast
 - Run examples from parent folder directly
 
 ```bash
-poetry run python examples/request_data.py
+python examples/request_data.py
 ```
 
 Or from Python interpreter:
 
 ```bash
-poetry run python
+python
 >>> import examples
+# To list available examples
 >>> help(examples)
+# Run example
 >>> examples.create_public_key()
 ```