Update changelog and readme for release v1.23.0

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

CHANGELOG.md

@@ -1,5 +1,24 @@
 # Changelog
 
+## [1.23.0] - 2021-02-11 - Seonyudo (선유도, 仙遊島)
+
+Support changes from NeoFS API v2.3.0 "Seonyudo" release.
+
+### Added
+
+- Fulfill backup factor for default attribute in placement.
+- Support of `Container.AnnounceUsedSpace` RPC from NeoFS API.
+- New `pkg/client.Client.AnnounceContainerUsedSpace` method.
+- Support of `STRING_NOT_EQUAL` and `NOT_PRESENT` object search filters.
+- Implementation of `json.Marshaler`/`json.Unmarshaler` on `v2/object/SearchFilter`.
+- Implementation of `json.Marshaler`/`json.Unmarshaler` on `pkg/object/SearchFilters`.
+- Named constants of well-known node attributes in `pkg/netmap`.
+
+### Renamed
+
+- `pkg/netmap/PriceAttr` to `pkg/netmap/AttrPrice`.
+- `pkg/netmap/CapacityAttr` to `pkg/netmap/AttrCapacity`.
+
 ## [1.22.2] - 2021-01-27
 
 ### Fixed
@@ -534,3 +553,4 @@ Initial public release
 [1.22.0]: https://github.com/nspcc-dev/neofs-api-go/compare/v1.21.2...v1.22.0
 [1.22.1]: https://github.com/nspcc-dev/neofs-api-go/compare/v1.22.0...v1.22.1
 [1.22.2]: https://github.com/nspcc-dev/neofs-api-go/compare/v1.22.1...v1.22.2
+[1.23.0]: https://github.com/nspcc-dev/neofs-api-go/compare/v1.22.2...v1.23.0

README.md

@@ -25,6 +25,7 @@ versions and SDK layer working with all of them in a handy way.
 |v1.20.x|[v2.0.2](https://github.com/nspcc-dev/neofs-api/releases/tag/v2.0.2)|
 |v1.21.x|[v2.1.0](https://github.com/nspcc-dev/neofs-api/releases/tag/v2.1.0)|
 |v1.22.x|[v2.2.0](https://github.com/nspcc-dev/neofs-api/releases/tag/v2.2.0)|
+|v1.23.x|[v2.3.0](https://github.com/nspcc-dev/neofs-api/releases/tag/v2.3.0)|
 
 
 ## Contributing