added demo to snapshots

Author: willmcgugan

CHANGELOG.md

@@ -25,6 +25,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - Type selectors can now contain numbers https://github.com/Textualize/textual/issues/1253
 - Fixed visibility not affecting children https://github.com/Textualize/textual/issues/1313
+- Fixed issue with auto width/height and relative children https://github.com/Textualize/textual/issues/1319
 
 ## [0.5.0] - 2022-11-20