Update changelog (#557)

## Introduced changes

updates changelog

## Breaking changes

## Checklist

<!-- Make sure all of these are complete -->

- [X] Linked relevant issue
- [X] Updated relevant documentation
- [X] Added relevant tests
- [X] Performed self-review of the code
- [X] Added changes to `CHANGELOG.md`

Author: THenry14

CHANGELOG.md

@@ -24,6 +24,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Support for custom networks - accounts created on custom networks are saved in `accounts-file` under network's
   chain_id
 - `accounts-file` field in Scarb.toml profile
+- Include the class hash of an account contract in the `accounts-file`
 
 #### Removed