Formatting cleanups, fixed all warnings in markdowner.py and adapted GH Action to no longer allow warnings #653

	name: Run markdowner.py on all markdown files and see if there are changes

	on:
	push:
	branches: [ master ]
	pull_request:
	branches: [ master ]
	workflow_dispatch:

	jobs:
	check:
	runs-on: ubuntu-latest
	steps:
	- name: Checks-out repository
	uses: actions/checkout@v2
	- name: Set up Python 3.7
	uses: actions/setup-python@v2
	with:
	python-version: "3.7"
	- name: Run markdowner.py to (hopefully not) edit markdown files
	run: \|
	find . -name '*.markdown' -type f -exec python3 .github/workflows/markdowner.py {} all \; \| tee output.log
	- name: Check output.log file for warnings
	run: \|
	! grep WARNING output.log
	- name: Check if there are changes
	run: \|
	git diff --exit-code

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