add release notes for v0.5.0

Author: strider2038

RELEASE_NOTES.md

@@ -0,0 +1,27 @@
+# Release notes
+
+## v0.5.0
+
+**Native `log/slog` integration.** This release replaces the custom field system with `slog.Attr` as the core type for error attributes. The logrus adapter has been removed.
+
+### Highlights
+
+- **`slog.Attr` everywhere** — Use `slog.String()`, `slog.Int()`, `slog.Group()`, etc. directly in `errors.Wrap()` and `errors.Errorf()` alongside existing options.
+- **`errors.Attrs(err)`** — Extract all attributes from an error chain for custom logging.
+- **`errors.Log(ctx, logger, err)`** — Log an error at Error level with attributes and stack trace.
+- **`errors.LogLevel(ctx, logger, level, err)`** — Same as above with an explicit level (Debug, Info, Warn, Error).
+- **New attribute options** — `Int64`, `Uint64`, `Float64`, `Any`. `Value` is deprecated in favor of `Any`.
+- **Grouped attributes** — Full support for `slog.Group` in errors, JSON marshaling, and `%+v` formatting (dot notation).
+- **`slog.LogValuer`** — Errors implement `LogValuer` for native slog handling.
+
+### Breaking changes
+
+- Custom `Field` types and `FieldLogger` are removed; use `slog.Attr` and `*slog.Logger`.
+- `LoggableError` now requires `Attrs() []slog.Attr` instead of `LogFields(FieldLogger)`.
+- `errors.Log(err, logger)` replaced by `errors.Log(ctx, logger, err)`.
+- Package requires **Go 1.21+**.
+- **logrus adapter removed** — see migration guide for a small custom adapter if needed.
+
+### Migration
+
+**If you are upgrading from v0.4.x, read the [Migration Guide](https://github.com/muonsoft/errors/blob/main/MIGRATION.md)** for step-by-step instructions and before/after examples.