add full-icu faq entry to readme

readme.md

@@ -26,6 +26,7 @@
   * [Can I configure the lighthouse run?](#can-i-configure-the-lighthouse-run)
   * [How does Lighthouse use network throttling, and how can I make it better?](#how-does-lighthouse-use-network-throttling-and-how-can-i-make-it-better)
   * [Are results sent to a remote server?](#are-results-sent-to-a-remote-server)
+  * [How do I get localized Lighthouse results?](#how-do-i-get-localized-lighthouse-results)
   * [How do I author custom audits to extend Lighthouse?](#how-do-i-author-custom-audits-to-extend-lighthouse)
   * [How do I contribute?](#how-do-i-contribute)
 
@@ -442,6 +443,10 @@ Read more in our [guide to network throttling](./docs/throttling.md).
 Nope. Lighthouse runs locally, auditing a page using a local version of the Chrome browser installed on the
 machine. Report results are never processed or beaconed to a remote server.
 
+### How do I get localized Lighthouse results via the CLI?
+
+Starting in Lighthouse 8.0, the `Intl` API is no longer polyfilled. If you're using Node 13 or later there should be no issue because Node is now [built with `full-icu` by default](https://nodejs.medium.com/node-js-12-to-lts-and-node-js-13-is-here-e28d6a4a2bd#9514), but if you're somehow stuck with `small-icu` and see Lighthouse log messages about your locale not being available, you can manually install ICU data by using the [`full-icu`](https://www.npmjs.com/package/full-icu) module and the [`--icu-data-dir` node flag](https://nodejs.org/api/intl.html#intl_providing_icu_data_at_runtime) at launch.
+
 ### How do I author custom audits to extend Lighthouse?
 
 > **Tip**: see [Lighthouse Architecture](./docs/architecture.md) for more information