extensions/markdown-language-features/src/markdownEngine.ts/MarkdownEngine/addLinkValidator
class MarkdownEngine:	private addLinkValidator(md: MarkdownIt): void {
		const validateLink = md.validateLink;
		md.validateLink = (link: string) => {
			return validateLink(link)
				|| isOfScheme(Schemes.vscode, link)
				|| isOfScheme(Schemes['vscode-insiders'], link)
				|| /^data:image\/.*?;/.test(link);
		};
	}