Update changelog

Author: 17o2

docs/CHANGELOG.md

@@ -2,6 +2,22 @@
 
 ## [0.4](https://github.com/formatc1702/WireViz/tree/v0.4) (20XX-XX-XX)
 
+### Backward-incompatible changes
+- New syntax for autogenerated components ([#184](https://github.com/wireviz/WireViz/issues/184), [#186](https://github.com/wireviz/WireViz/pull/186))
+- New command line interface ([#244](https://github.com/wireviz/WireViz/pull/244))
+
+
+### New features
+
+- Allow mates between connectors ([#134](https://github.com/wireviz/WireViz/issues/134), [#186](https://github.com/wireviz/WireViz/pull/186))
+- Improve technical drawing output ([#74](https://github.com/wireviz/WireViz/pull/74), [#32](https://github.com/wireviz/WireViz/issues/32), [#239](https://github.com/wireviz/WireViz/pull/239))
+- Embed images in SVG output ([#189](https://github.com/wireviz/WireViz/pull/189))
+
+
+### Misc. fixes
+- Use `isort` and `black` for cleaner code and easier merging ([#248](https://github.com/wireviz/WireViz/pull/248))
+- Code improvements ([#246](https://github.com/wireviz/WireViz/pull/246), [#250](https://github.com/wireviz/WireViz/pull/250))
+
 
 ## [0.3.1](https://github.com/formatc1702/WireViz/tree/v0.3.1) (2021-10-25)