message: Fix updateBaseTag README typo.
diff: @@ -255,13 +255,13 @@ const buildStream = mergeStream(project.sources(), project.dependencies());
  const unbundledBuildStream = forkStream(buildStream)
  // This build will be served from http://example.com/unbundled/
  - .updateBaseTag('/unbundled/')
  + .pipe(project.updateBaseTag('/unbundled/'))
  .pipe(gulp.dest('build/unbundled'));
  const bundledBuildStream = forkStream(buildStream)
  .pipe(project.bundler())
  // While this build will be served from http://example.com/bundled/
  - .updateBaseTag('/bundled/')
  + .pipe(project.updateBaseTag('/bundled/'))
  .pipe(gulp.dest('build/bundled'));
  ```
  