Fix invalid standard names, add standard name checking script and github action #25

	name: Pull request checks

	on:
	pull_request:

	jobs:
	check-unique-standard-names:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v3

	- uses: actions/setup-python@v4
	with:
	python-version: "3.x"

	- name: Install xmllint
	run: \|
	sudo apt-get update
	sudo apt-get -y install libxml2-utils

	- name: Check for duplicate standard names
	run: tools/check_xml_unique.py standard_names.xml

	check-rerendered-markdown:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v3

	- uses: actions/setup-python@v4
	with:
	python-version: "3.x"

	- name: Install xmllint
	run: \|
	sudo apt-get update
	sudo apt-get -y install libxml2-utils

	- name: Check markdown has been rerendered
	run: \|
	# Checks if the saved markdown matches freshly rendered markdown.
	# If this fails you have likely forgotten to rerun the write script
	# after adding a new name, or updating its description.
	checksum=$(sha256sum Metadata-standard-names.md)
	tools/write_standard_name_table.py standard_names.xml
	test "$checksum" = "$(sha256sum Metadata-standard-names.md)"

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