src/vs/platform/localizations/node/localizations.ts/LocalizationsService/getLanguageIds
class LocalizationsService:	async getLanguageIds(): Promise<string[]> {
		const languagePacks = await this.cache.getLanguagePacks();
		// Contributed languages are those installed via extension packs, so does not include English
		const languages = ['en', ...Object.keys(languagePacks)];
		return distinct(languages);
	}