Update changelog

Author: JulianVennen

CHANGELOG.md

@@ -1,3 +1,8 @@
+## Breaking Changes
+- `MclogsClient#uploadLog(Path)` now throws an ExecutionException if reading the file fails
+  instead of throwing an IOException immediately.
+
+## Improvements
 - Add endpoint for analysing a log without storing it
 - Add endpoint for fetching storage limits
 - Use instance limits for truncating logs passed by their path