Add an initial changelog for the v3.4.0 release

CHANGELOG.md

@@ -1,5 +1,16 @@
 # Changelog
 
+## 3.4.0 - QR code support and backend rewrite
+- QR codes can now be generated for easily sending items to [supported apps](https://github.com/Jacalz/rymdport/wiki/Supported-clients#clients-with-qr-code-scanning) (fixes #10).
+- Rewrote a large part of the backend for displaying sends and receives.
+ - Progress bars no longer display the wrong percentage sometimes.
+ - Fixes a potential crash that could happen sometimes when sending.
+- Added support for removing items that have completed the transfer (fixes #32).
+- Added keyboard shortcuts for switching between tabs. See the [Keyboard Shortcuts](https://github.com/Jacalz/rymdport/wiki/Keyboard-shortcuts) for more information.
+- Added an option to disable update checking on startup for release binaries (fixes #66).
+- The receive page now shows which code a received item came from.
+- Various improvements to performance and memory usage.
+
 ## 3.3.6 - Crash fix for copying received text
 - Fixed a crash when pressing the copy button in the text receive window (fixes #83).
 - Fixed the AppStream metadata not containing the v3.3.5 release information.