Update README with content from brief announcement. #855

	name: cmake-format check

	on:
	push:
	branches:
	- main
	pull_request:
	workflow_dispatch:
	jobs:
	cmake-formatting-check:
	name: CMake Formatting Check
	runs-on: self-hosted
	container:
	image: "localhost:5000/kamping-ci"
	steps:
	- name: Checkout repository
	uses: actions/checkout@v3
	- name: Delete extern directory
	# Very hacky but the action doesn't allow excluding directories
	# and for some reason the checkout action checks out submodules even though it shouldn't
	run: rm -rf ./extern
	- name: Format CMake files
	id: cmake-format
	uses: Hespian/cmake-format-action@main
	with:
	args: --config-files .cmake-format.py --check

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