Update CHANGELOG.md

Author: MalteHerrmann

CHANGELOG.md

@@ -39,6 +39,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Improvements
 
+- [#7](https://github.com/MalteHerrmann/upgrade-local-node-go/pull/7) Add linters plus corresponding refactors
 - [#6](https://github.com/MalteHerrmann/upgrade-local-node-go/pull/6) Restructuring and refactoring
 - [#4](https://github.com/MalteHerrmann/upgrade-local-node-go/pull/4) Add GH actions and Makefile for testing
 - [#3](https://github.com/MalteHerrmann/upgrade-local-node-go/pull/3) Use broadcast mode `sync` instead of `block`