src/vs/platform/files/common/fileService.ts/FileService/createFolder
class FileService:	async createFolder(resource: URI): Promise<IFileStatWithMetadata> {
		const provider = this.throwIfFileSystemIsReadonly(await this.withProvider(resource), resource);

		// mkdir recursively
		await this.mkdirp(provider, resource);

		// events
		const fileStat = await this.resolve(resource, { resolveMetadata: true });
		this._onDidRunOperation.fire(new FileOperationEvent(resource, FileOperation.CREATE, fileStat));

		return fileStat;
	}