Run a CI job linting/parsing the CMake files in cmake/* #18

	name: CMake Linter

	on: [push, pull_request]

	jobs:
	run_cmakelint:
	runs-on: ubuntu-latest
	steps:
	- name: Checkout
	uses: actions/checkout@master

	- name: Set up Python
	uses: actions/setup-python@v2
	with:
	python-version: 3.8

	- name: Install cmakelint
	run: \|
	python -m pip install --upgrade pip
	# cmake-lint does not find real problems with CMAke syntax
	python -m pip install cmakelang

	- name: run cmake-lint
	working-directory: ${{github.workspace}}
	run: \|
	cmake-lint --version
	for f in cmake/*.cmake; do
	echo "Processing ${f}"
	cmake-lint -c tools/cmakelang-config.py -- $f
	done

Provide feedback