Update README.md: Comment more on extensibility #111

	name: Python package

	on: [push]

	# NOTE: Keep this file in sync with the Dockerfile in the root directory

	jobs:
	build:
	# We do not want to waste resources, and our tests are likely to deadlock once in a while when developing
	timeout-minutes: 30

	runs-on: ubuntu-latest
	strategy:
	fail-fast: false # Tests may behave very different across these systems
	matrix:
	# We do not test on ros:foxy-ros-core, since it causes many problems in the CI pipeline
	# TODO: add ros:iron-ros-core when it is available
	container: ["ros:humble-ros-core", "ros:rolling-ros-core"]
	container: ${{ matrix.container }}

	defaults:
	run:
	shell: bash
	steps:
	-
	name: Checkout repository
	uses: actions/checkout@v3
	-
	name: Install dependencies and the package
	run: \|
	apt-get update -q && apt-get install -qy python3-pip python-is-python3 ros-$ROS_DISTRO-example-interfaces
	pip install --upgrade pip setuptools
	python -m pip install -e '.[dev]'
	-
	name: Format (with black)
	run: \|
	black --check .
	-
	name: Lint (with ruff)
	run: \|
	ruff check .
	-
	name: Type check main code (with mypy)
	run: \|
	mypy ros2_easy_test
	-
	name: Type check tests (with mypy)
	continue-on-error: true # We do not want to fail the build if the type checker fails on the tests
	run: \|
	mypy tests
	-
	name: Testing (with pytest)
	run: \|
	source /opt/ros/$ROS_DISTRO/setup.bash # Activate ROS
	python -m pytest

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