Add output-url to changelog

CHANGELOG.md

@@ -7,6 +7,7 @@
 - Change names of individual taxonomies to be plural (ie `tags/my-tag` instead of `tag/my-tag`)
 - Update to Tera 0.11
 - Better UX on first `serve` thanks to some default templates.
+- Add `output-dir` to `build` and `serve` to generate the site in a folder other than `public`
 
 ## 0.2.2 (2017-11-01)