Update the ChangeLog with some recent changes/fixes

Author: davep

CHANGELOG.md

@@ -10,12 +10,16 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ### Fixed
 
 - Fixed issue where scrollbars weren't being unmounted
+- Fixed how the app title in a `Header` is centred https://github.com/Textualize/textual/issues/1060
+- Fixed the swapping of button variants https://github.com/Textualize/textual/issues/1048
+- Fixed reserved characters in screenshots https://github.com/Textualize/textual/issues/993
 
 ### Changed
 
 - DOMQuery now raises InvalidQueryFormat in response to invalid query strings, rather than cryptic CSS error
 - Dropped quit_after, screenshot, and screenshot_title from App.run, which can all be done via auto_pilot
 - Widgets are now closed in reversed DOM order
+- Changed `textual run` so that it patches `argv` in more situations
 
 ### Added