Update CHANGELOG.md (RenderObject drawing approach, might fix #556, #582

, #584, #591).

CHANGELOG.md

@@ -1,5 +1,5 @@
 ## newVersion
-* [IMPROVEMENT] We now use [RenderObject](https://api.flutter.dev/flutter/rendering/RenderObject-class.html) as our default drawing system. It brings a lot of stability. Such as size handling, hitTest handling (touches), and It makes us possible to paint Widgets inside our chart (It might fix #591, #584, #556, #582 .
+* [IMPROVEMENT] We now use [RenderObject](https://api.flutter.dev/flutter/rendering/RenderObject-class.html) as our default drawing system. It brings a lot of stability. Such as size handling, hitTest handling (touches), and It makes us possible to paint Widgets inside our chart (It might fix #556, #582, #584, #591).
 * [IMPROVEMENT] Added [Radar Chart Documentations](https://github.com/imaNNeoFighT/fl_chart/blob/master/repo_files/documentations/radar_chart.md)
 * [IMPROVEMENT] Added `textAlign` property in the [BarTooltipItem](https://github.com/imaNNeoFighT/fl_chart/blob/master/repo_files/documentations/bar_chart.md#bartooltipitem), [LineTooltipItem](https://github.com/imaNNeoFighT/fl_chart/blob/master/repo_files/documentations/line_chart.md#linetooltipitem), and [ScatterTooltipItem](https://github.com/imaNNeoFighT/fl_chart/blob/master/repo_files/documentations/scatter_chart.md#scattertooltipitem), default is `TextAlign.center`.
 * [IMPROVEMENT] Added `direction` property in the [BarTouchTooltipData](https://github.com/imaNNeoFighT/fl_chart/blob/master/repo_files/documentations/bar_chart.md#bartouchtooltipdata), and [LineTouchTooltipData](https://github.com/imaNNeoFighT/fl_chart/blob/master/repo_files/documentations/line_chart.md#linetouchtooltipdata) to specify the position of the tooltip (can be `auto`, `top`, `bottom`), default is `auto`.