chore: update README.md based on feedback from Product (#945)

Author: jdstrand

README.md

@@ -6,6 +6,8 @@
 
 This is the official (and community-maintained) Java client library for [InfluxDB](https://www.influxdata.com/products/influxdb-overview/) (1.x), the open source time series database that is part of the TICK (Telegraf, InfluxDB, Chronograf, Kapacitor) stack.
 
+For InfluxDB 3.0 users, this library is succeeded by the lightweight [v3 client library](https://github.com/InfluxCommunity/influxdb3-java).
+
 _Note: This library is for use with InfluxDB 1.x and [2.x compatibility API](https://docs.influxdata.com/influxdb/v2.0/reference/api/influxdb-1x/). For full supports of InfluxDB 2.x features, please use the [influxdb-client-java](https://github.com/influxdata/influxdb-client-java) client._
 
 ## Adding the library to your project