Add link to s3-notifier

Author: allthesignals

README.md

@@ -209,7 +209,7 @@ server.start();
 
 ### Available Notifiers
 
-* fastboot-s3-notifier
+* [fastboot-s3-notifier](https://github.com/ember-fastboot/fastboot-s3-notifier)
 * [fastboot-fs-notifier](https://github.com/iheanyi/fastboot-fs-notifier)
 * [fastboot-watch-notifier](https://github.com/pwfisher/fastboot-watch-notifier)
 
@@ -242,4 +242,4 @@ let server = new FastBootAppServer({
 
 ### Twitter and LinkedIn
 
-As of 2019-06-06, Twitter and LinkedIn's scrapers have a hard time extracting your site's metadata for sharing if `chunkedResponse` is set to `true` in your `server.js` file. Set `chunkedResponse: false` if your meta tags are in place but the [Twitter card validator](https://cards-dev.twitter.com/validator) shows "Card not found" or [LinkedIn's Post Inspector](https://www.linkedin.com/post-inspector/) shows a 500 error.
+As of 2019-06-06, Twitter and LinkedIn's scrapers have a hard time extracting your site's metadata for sharing if `chunkedResponse` is set to `true` in your `server.js` file. Set `chunkedResponse: false` if your meta tags are in place but the [Twitter card validator](https://cards-dev.twitter.com/validator) shows "Card not found" or [LinkedIn's Post Inspector](https://www.linkedin.com/post-inspector/) shows a 500 error.