extensions/markdown-language-features/src/preview/documentRenderer.ts/MdDocumentRenderer/_getSettingsOverrideStyles
class MdDocumentRenderer:	private _getSettingsOverrideStyles(config: MarkdownPreviewConfiguration): string {
		return [
			config.fontFamily ? `--markdown-font-family: ${config.fontFamily};` : '',
			isNaN(config.fontSize) ? '' : `--markdown-font-size: ${config.fontSize}px;`,
			isNaN(config.lineHeight) ? '' : `--markdown-line-height: ${config.lineHeight};`,
		].join(' ');
	}