Merge pull request element-hq#18872 from psrpinto/labs-doc-layout-switcher

Document missing features in labs.md

Author: turt2live

docs/labs.md

@@ -133,3 +133,7 @@ and notification noises are suppressed. Not perfect, but can help reduce noise.
 ## Hidden read receipts (`feature_hidden_read_receipts`)
 
 Enables sending hidden read receipts as per [MSC2285](https://github.com/matrix-org/matrix-doc/pull/2285)
+
+## New layout switcher (with message bubbles) (`feature_new_layout_switcher`)
+
+Adds a "Message layout" section under `Settings -> Appearance`, where the user can select their preferred message layout (e.g. IRC or Modern). Additionally, adds a new "Message bubbles" layout.