Add deprecated notice to the project (#106)

If other contributors decide to own this sub-project and keep updating this or other language SDKs, we are open to that.

However, for now, we will implement the client directly in the SkyWalking OAP backend, as the current logic is simple enough and has eliminated the client cache and column-index writing.

README.md

diff --git a/README.md b/README.md
index 1922d14..93784de 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,13 @@
-BanyanDB Java Client
+~~BanyanDB Java Client~~
 ==========
 
+# Deprecated
+**Don't plan to update Java Client SDK since BanyanDB 0.9.0.**
+Since version 0.10.0, BanyanDB has introduced schema-based validation for all write operations.
+We recommend users switch to local implementation according to the [gRPC/HTTP protobuf definitions](https://github.com/apache/skywalking-banyandb-client-proto).
+
+----
+
 <img src="http://skywalking.apache.org/assets/logo.svg" alt="Sky Walking logo" height="90px" align="right" />
 
 The client implement for SkyWalking BanyanDB in Java.
@@ -8,8 +15,6 @@
 [![GitHub stars](https://img.shields.io/github/stars/apache/skywalking.svg?style=for-the-badge&label=Stars&logo=github)](https://github.com/apache/skywalking)
 [![Twitter Follow](https://img.shields.io/twitter/follow/asfskywalking.svg?style=for-the-badge&label=Follow&logo=twitter)](https://twitter.com/AsfSkyWalking)
 
-[![CI/IT Tests](https://github.com/apache/skywalking-banyandb-java-client/workflows/CI%20AND%20IT/badge.svg?branch=main)](https://github.com/apache/skywalking-banyandb-java-client/actions?query=workflow%3ACI%2BAND%2BIT+event%3Aschedule+branch%main)
-
 # Usage
 
 ## Create a client