Update CHANGELOG.

Author: rodrigogiraoserrao

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - Added "inherited bindings" -- BINDINGS classvar will be merged with base classes, unless inherit_bindings is set to False
 - Added `Tree` widget which replaces `TreeControl`.
+- Added widget `Placeholder` https://github.com/Textualize/textual/issues/1200.
 
 ### Changed
 
@@ -46,7 +47,6 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Support lazy-instantiated Screens (callables in App.SCREENS) https://github.com/Textualize/textual/pull/1185
 - Display of keys in footer has more sensible defaults https://github.com/Textualize/textual/pull/1213
 - Add App.get_key_display, allowing custom key_display App-wide https://github.com/Textualize/textual/pull/1213
-- Added widget `Placeholder`
 
 ### Changed