changelog: Document changes up to latest

Author: chrisbobbe

docs/changelog.md

@@ -39,6 +39,34 @@ It doesn't include
 
 ## Unreleased
 
+### Highlights for users
+
+* The mobile app will no longer connect to Zulip Server versions older than
+  2.0, which was released in 2019. Versions older than 3.0 are unsupported,
+  and server administrators should upgrade. (#5102)
+* (iOS) Fixed a bug where links to uploaded files would sometimes lead to an
+  error page instead of the file. (#4136)
+* Fixed a bug where no feedback was given when you tapped a link that
+  couldn't be opened. (#5518)
+
+Plus, like every release, other fixes and improvements for your Zulip
+experience.
+
+
+### Highlights for developers
+
+* We expect that classnames ending in "Error" are no longer minified, making
+  it easier to debug Sentry crash reports. (PR #5177)
+* We added an `intl` suite to `tools/test` to automate some checks on our
+  translation data. (PR #5476)
+* We now use tsc-generated versions of shared code. (PR #5628)
+* We have migrated to @react-native-clipboard/clipboard, fixing some
+  deprecation warnings. (PR #5648)
+* We fixed some small edge-case bugs with switching accounts and removing
+  accounts. (PR #5634)
+
+Resolved issues: #4136, #5518, PR #5634, PR #5177, #5102, #5534
+
 
 ## 27.199 (2023-01-19)