extensions/markdown-language-features/src/markdownEngine.ts/MarkdownItEngine/constructor
class MarkdownItEngine:	public constructor(
		private readonly contributionProvider: MarkdownContributionProvider,
		slugifier: Slugifier,
		private readonly logger: ILogger,
	) {
		this.slugifier = slugifier;

		contributionProvider.onContributionsChanged(() => {
			// Markdown plugin contributions may have changed
			this.md = undefined;
		});
	}