src/vs/workbench/contrib/localizations/browser/localizationsActions.ts/ConfigureLocaleAction/getLanguageOptions
class ConfigureLocaleAction:	private async getLanguageOptions(): Promise<IQuickPickItem[]> {
		const availableLanguages = await this.localizationService.getLanguageIds();
		availableLanguages.sort();

		return availableLanguages
			.map(language => { return { label: language }; })
			.concat({ label: localize('installAdditionalLanguages', "Install Additional Languages...") });
	}