Add changelog entry

distribution/changelog.txt

@@ -2,8 +2,10 @@
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 - Feature: [#622] Add option to align the top toolbar buttons horizontally centred (off by default).
 - Feature: [#21714] [Plugin] Costume assignment is now tailored to each staff type.
+- Feature: [#21853] Enlarged UI mode.
 - Feature: [#21893] On launch, the game now indicates what system is being initialised.
 - Feature: [#21913] [Plugin] Allow precise and safe control of peep animations.
+- Improved: [#21853] Dropdowns now automatically use multiple columns if they are too tall for the screen.
 - Improved: [#21981] Rendering performance of the map window has been improved considerably.
 - Improved: [#21981] The map window now defaults to showing as much of the map as fits the screen.
 - Improved: [#21983] Taking a screenshot now shows a message again, closing when taking another.