Updated CHANGELOG.md

Author: zonia3000

CHANGELOG.md

@@ -1,6 +1,6 @@
 Note: Numbers like (#123) point to closed Pull Requests on the fractal-vizarr-viewer repository.
 
-# Unreleased
+# 0.4.0
 
 * Separated fractal-data from vizarr, renamed repository to `fractal-data` (\#64);
 * Added `BIND_ADDRESS` environment variable, defaulting to `0.0.0.0` for IPv4 binding (\#64);