docs: update CHANGELOG for v1.1.0

Author: okaryo

CHANGELOG.md

@@ -1,3 +1,9 @@
+## 1.1.0
+* Add `preloadIndexes` Property for Advanced Element Preloading in [#6](https://github.com/okaryo/lazy_load_indexed_stack/pull/6)
+
+## 1.0.1
+* Fix dynamic generation of children causes  overflow in [#4](https://github.com/okaryo/lazy_load_indexed_stack/pull/4)
+
 ## 1.0.0
 * Update required sdk version to `^3.0.0`