Update the changelog

Author: HoonBaek

CHANGELOG.md

@@ -3,8 +3,8 @@
 ## [v3.14.7] (May 23, 2024)
 ### Fixes
 * Fixed issue where files that failed to compress were not being sent
-* Cleaned up the props of the ChannelSettings component to ensure all missed props are applied
-* Exported the ChannelSettingsHeader component as default
+* Cleaned up the props of the `ChannelSettings` component to ensure all missed props are applied
+* Exported the `ChannelSettingsHeader` component as default
   ```
   import ChannelSettingsHeader from '@sendbird/uikit-react/ChannelSettings/components/ChannelSettingsHeader'
   ```
@@ -14,6 +14,9 @@
 * Implemented an attempt to load based on screen size threshold
 * Added `data-testid` to the UI components for making it easily to select them in the QE test
 
+### Features
+* Added `MESSAGE_INPUT__PLACE_HOLDER__FROZEN` to StringSet: `'Chat is unavailable in this channel'`
+
 ## [v3.14.6] (May 10, 2024)
 ### Fixes
 * Fixed a bug where import statements are not located at the top of the extracted index.css file