Update labs.md

Author: novocaine

docs/labs.md

@@ -137,3 +137,7 @@ Enables sending hidden read receipts as per [MSC2285](https://github.com/matrix-
 ## 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.
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+## Pseudonymous Analytics opt-in
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+Opts in to collection of pseudonymous analytics data via Posthog. See https://github.com/matrix-org/matrix-react-sdk/pull/6495