Add missing things to changelog

Add info about changed `Crawler::addStep()` signature and removal of the
`UnknownLoaderKeyException`.

CHANGELOG.md

@@ -11,7 +11,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * __BREAKING__: Removed methods `BaseStep::addToResult()`, `BaseStep::addLaterToResult()`, `BaseStep::addsToOrCreatesResult()`, `BaseStep::createsResult()`, and `BaseStep::keepInputData()`. These methods were deprecated in v1.8.0 and should be replaced with `Step::keep()`, `Step::keepAs()`, `Step::keepFromInput()`, and `Step::keepInputAs()`.
 * __BREAKING__: With the removal of the `addToResult()` method, the library no longer uses `toArrayForAddToResult()` methods on output objects. Instead, please use `toArrayForResult()`. Consequently, `RespondedRequest::toArrayForAddToResult()` has been renamed to `RespondedRequest::toArrayForResult()`.
 * __BREAKING__: Removed the `result` and `addLaterToResult` properties from `Io` objects (`Input` and `Output`). These properties were part of the `addToResult` feature and are now removed. Instead, use the `keep` property where kept data is added.
-* __BREAKING__: The return type of the `Crawler::loader()` method no longer allows `array`. This means it's no longer possible to provide multiple loaders from the crawler. Instead, use the new functionality to directly provide a custom loader to a step described below.
+* __BREAKING__: The signature of the `Crawler::addStep()` method has changed. You can no longer provide a result key as the first parameter. Previously, this key was passed to the `Step::addToResult()` method internally. Now, please handle this call yourself.
+* __BREAKING__: The return type of the `Crawler::loader()` method no longer allows `array`. This means it's no longer possible to provide multiple loaders from the crawler. Instead, use the new functionality to directly provide a custom loader to a step described below. As part of this change, the `UnknownLoaderKeyException` was also removed as it is now obsolete. If you have any references to this class, please make sure to remove them.
 * __BREAKING__: Refactored the abstract `LoadingStep` class to a trait and removed the `LoadingStepInterface`. Loading steps should now extend the `Step` class and use the trait. As multiple loaders are no longer supported, the `addLoader` method was renamed to `setLoader`. Similarly, the methods `useLoader()` and `usesLoader()` for selecting loaders by key are removed. Now, you can directly provide a different loader to a single step using the trait's new `withLoader()` method (e.g., `Http::get()->withLoader($loader)`).
 * __BREAKING__: Removed the `PaginatorInterface` to allow for better extensibility. The old `Crwlr\Crawler\Steps\Loading\Http\Paginators\AbstractPaginator` class has also been removed. Please use the newer, improved version `Crwlr\Crawler\Steps\Loading\Http\AbstractPaginator`. This newer version has also changed: the first argument `UriInterface $url` is removed from the `processLoaded()` method, as the URL also is part of the request (`Psr\Http\Message\RequestInterface`) which is now the first argument. Additionally, the default implementation of the `getNextRequest()` method is removed. Child implementations must define this method themselves. If your custom paginator still has a `getNextUrl()` method, note that it is no longer needed by the library and will not be called. The `getNextRequest()` method now fulfills its original purpose.
 * __BREAKING__: Removed methods from `HttpLoader`: