Add Ascend to adopters (bazelbuild#686)

Author: smparkes

README.md

@@ -753,6 +753,7 @@ See [CONTRIBUTING.md](CONTRIBUTING.md) for more info.
 
 Here's a (non-exhaustive) list of companies that use `rules_scala` in production. Don't see yours? [You can add it in a PR](https://github.com/bazelbuild/rules_scala/edit/master/README.md)!
 
+* [Ascend](https://ascend.io/)
 * [Etsy](https://www.etsy.com/)
 * [Kitty Hawk](https://kittyhawk.aero/)
 * [Meetup](https://meetup.com/)