Update type of MediaMetadata's artwork #153

	# Workflow based on the main w3c/spec-prod action example:
	# https://github.com/w3c/spec-prod/#basic-usage

	name: Build, Validate, Deploy and Publish

	on:
	# Worflow runs on pull requests where it makes sure that the spec can still be
	# generated, that markup is valid and that there are no broken links, as
	# well as on pushes to the default branch where it also deploys the generated
	# spec to the gh-pages branch and publishes the result to /TR.
	# The "workflow_dispatch" hook allows admins to also trigger the workflow
	# manually from GitHub's UI.
	pull_request: {}
	push:
	branches: [main]
	workflow_dispatch:

	jobs:
	main:
	runs-on: ubuntu-20.04
	steps:
	# See doc at https://github.com/actions/checkout#checkout-v2
	- name: Checkout repository
	uses: actions/checkout@v2

	# See doc at https://github.com/w3c/spec-prod/#spec-prod
	# The action only deploys the generated spec to the gh-pages branch when
	# the workflow was triggered by a push to the default branch.
	- name: Build and validate index.html, push to gh-pages branch if needed
	uses: w3c/spec-prod@v2
	with:
	GH_PAGES_BRANCH: gh-pages
	W3C_ECHIDNA_TOKEN: ${{ secrets.ECHIDNA_TOKEN }}
	W3C_WG_DECISION_URL: https://github.com/w3c/media-wg/issues/27
	W3C_BUILD_OVERRIDE: \|
	status: WD

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