message: feat(preset-umi): add @ and alias
diff: @@ -20,6 +20,8 @@ function resolveProjectDep(opts: { pkg: any; cwd: string; dep: string }) {
  export default (api: IApi) => {
  const configDefaults: Record<string, any> = {
  alias: {
  + '@': api.paths.absSrcPath,
  + '@@': api.paths.absTmpPath,
  umi: process.env.UMI_DIR!,
  '@umijs/renderer-react': dirname(
  require.resolve('@umijs/renderer-react/package.json'),
  