chore: update CHANGELOG

Author: kkovaacs

CHANGELOG.md

@@ -16,6 +16,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Add `pathfinder_getClassProof` endpoint to retrieve the Merkle proof of any class hash in the class trie.
 - add `process_start_time_seconds` metric showing the unix timestamp when the process started.
 - `--log-output-json` CLI option has been added to output the Pathfinder log in line-delimited JSON.
+- Preliminary support has been added for the new JSON-RPC 0.8.0-rc1 specification.
 
 ### Changed