Fix "Running on device" in RNTester README (#32169)

Summary:
Fix broken link
## Changelog

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[CATEGORY] [TYPE] - Message

Pull Request resolved: https://github.com/facebook/react-native/pull/32169

Reviewed By: yungsters

Differential Revision: D30809096

Pulled By: GijsWeterings

fbshipit-source-id: b600e411c7292ba840e076d68f66cb3043887335

packages/rn-tester/README.md

@@ -35,7 +35,7 @@ _Note: Building for the first time can take a while._
 
 Open the RNTester app in your emulator.
 If you want to use a physical device, run `adb devices`, then `adb -s <device name> reverse tcp:8081 tcp:8081`.
-See [Running on Device](https://reactnative.dev/docs/running-on-device.html) for additional instructions on using a physical device.
+See [Running on Device](https://reactnative.dev/docs/running-on-device) for additional instructions on using a physical device.
 
 ### Running with Buck