message: Add changelog entry about wireformat and client impl
diff: @@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
  ## [Unreleased]
  ### Changed
  +* Add a Rust API client that implements the Northstar API protocol. See
  + `northstar::api::client`.
  +* Exchange the length encoded wire format with newline seperated json.
  * Upgrade to Tokio 1.0
  * Rename the default configuration file from north.toml to northstar.toml
  * The `[directories]` section in the `north.toml` configuration file is replaced
  