Update changelog with new GridLine type

RELEASES.md

@@ -6,12 +6,13 @@
 
 - `experimental_grid` feature named to just `grid`
 - `grid` feature enabled by default
+- `GridPlacement::Line` now stores a `GridLine` newtype wrapper around an `i16` rather than a raw `i16`. If you are using the style helpers then this change will not affect you.
+- *BREAKING:* `Position` is now renamed to `Inset` and is now in line with [CSS inset specs](https://developer.mozilla.org/en-US/docs/Web/CSS/inset)
+- *BREAKING:* `PositionType` is now renamed to `Position` and is now in line with [CSS position specs](https://developer.mozilla.org/en-US/docs/Web/CSS/position)
 
 ### Fixes
 
 - Flexbox nodes sized under a min-content constraint now size correctly (#291)
-- *BREAKING:* `Position` is now renamed to `Inset` and is now in line with [CSS inset specs](https://developer.mozilla.org/en-US/docs/Web/CSS/inset)
-- *BREAKING:* `PositionType` is now renamed to `Position` and is now in line with [CSS position specs](https://developer.mozilla.org/en-US/docs/Web/CSS/position)
 
 ### Removed