Add PR number

CHANGELOG.md

@@ -38,14 +38,15 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
   - `connectCarouselFilmStrip`: Fixed `botAvatarInitials` and `userAvatarInitials` functionality from [recent name change](https://github.com/Microsoft/BotFramework-WebChat/pull/1486),
   - `BasicTranscript`: Fixed user activity should not be recreated after receive ACK from Direct Line,
   - by [@corinagum](https://github.com/corinagum) in PR [#1528](https://github.com/Microsoft/BotFramework-WebChat/pull/1528)
-- Fix [#1539], outgoing typing indicators are not sent and acknowledged properly, in PR [#XXX](https://github.com/Microsoft/BotFramework-WebChat/pull/XXX)
+- Fix [#1539], outgoing typing indicators are not sent and acknowledged properly, in PR [#1541](https://github.com/Microsoft/BotFramework-WebChat/pull/1541)
 
 ### Removed
 - `botAvatarImage` and `userAvatarImage` props, as they are moved inside `styleOptions`, in PR [#1486](https://github.com/Microsoft/BotFramework-WebChat/pull/1486)
 
 ### Samples
 - UI: [Hide upload button](https://microsoft.github.io/BotFramework-WebChat/05.d.hide-upload-button-styling/), in [#1491](https://github.com/Microsoft/BotFramework-WebChat/pull/1491)
 - UI: [Avatar image](https://microsoft.github.io/BotFramework-WebChat/04.b.display-user-bot-images-styling/), in [#1486](https://github.com/Microsoft/BotFramework-WebChat/pull/1486)
+- UI: [Send typing](https://microsoft.github.io/BotFramework-WebChat/07.b.customization-send-typing), in [#1541](https://github.com/Microsoft/BotFramework-WebChat/pull/1541)
 
 ## [4.2.0] - 2018-12-11
 ### Added
@@ -103,7 +104,6 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Others: [Using Web Chat v3](https://microsoft.github.io/BotFramework-WebChat/webchat-v3/), in [#1287](https://github.com/Microsoft/BotFramework-WebChat/pull/1287)
 - Speech: [Cognitive Services Speech to Text and Text to Speech](https://github.com/Microsoft/BotFramework-WebChat/tree/master/samples/6.c.cognitive-services-speech-services-js) (both subscription key and authorization token flow)
 - Speech: [Cognitive Services Speech to Text using lexical result](https://github.com/Microsoft/BotFramework-WebChat/tree/master/samples/6.e.cognitive-services-speech-services-with-lexical-result) (text normalization)
-- UI: [Send typing](https://microsoft.github.io/BotFramework-WebChat/07.b.customization-send-typing), in [#XXX](https://github.com/Microsoft/BotFramework-WebChat/pull/XXX)
 
 ## [4.1.0] - 2018-10-31
 ### Added