docs: mention MinimalRouteData as feature in changelog (#301)

# Documentation
- Add `MinimalRouteData` to 0.3.0 changelog feature list

Author: LayZeeDK

CHANGELOG.md

@@ -7,6 +7,7 @@
 - Add factory for selecting specific route data: `RouterStore#selectRouteData`
 - Add route title to `MinimalActivatedRouteSnapshot#title`
 - Add route title selector: `RouterStore#title$`
+- Add type `MinimalRouteData` for serializable route data
 
 ### **BREAKING CHANGES**