src/vs/workbench/contrib/notebook/browser/view/renderers/backLayerWebView.ts/BackLayerWebView/getRendererData
class BackLayerWebView:	private getRendererData(): RendererMetadata[] {
		return this.notebookService.getRenderers().map((renderer): RendererMetadata => {
			const entrypoint = {
				extends: renderer.entrypoint.extends,
				path: this.asWebviewUri(renderer.entrypoint.path, renderer.extensionLocation).toString()
			};
			return {
				id: renderer.id,
				entrypoint,
				mimeTypes: renderer.mimeTypes,
				messaging: renderer.messaging !== RendererMessagingSpec.Never,
				isBuiltin: renderer.isBuiltin
			};
		});
	}