docs: add TiDB Cloud in README.md

README.md

@@ -1,11 +1,24 @@
 # TiFlash
+
 ![tiflash-architecture](tiflash-architecture.png)
 
-[TiFlash](https://docs.pingcap.com/tidb/stable/tiflash-overview) is a columnar storage component of [TiDB](https://docs.pingcap.com/tidb/stable). It mainly plays the role of Analytical Processing (AP) in the Hybrid Transactional/Analytical Processing (HTAP) architecture of TiDB.
+[TiFlash](https://docs.pingcap.com/tidb/stable/tiflash-overview) is a columnar storage component of [TiDB](https://docs.pingcap.com/tidb/stable) and [TiDB Cloud](https://en.pingcap.com/tidb-cloud/), the fully-managed service of TiDB. It mainly plays the role of Analytical Processing (AP) in the Hybrid Transactional/Analytical Processing (HTAP) architecture of TiDB.
 
 TiFlash stores data in columnar format and synchronizes data updates in real-time from [TiKV](https://github.com/tikv/tikv) by Raft logs with sub-second latency. Reads in TiFlash are guaranteed transactionally consistent with Snapshot Isolation level. TiFlash utilizes Massively Parallel Processing (MPP) computing architecture to accelerate the analytical workloads.
 
-TiFlash repository is based on [ClickHouse](https://github.com/ClickHouse/ClickHouse). We appreciate the excellent work of ClickHouse team.
+TiFlash repository is based on [ClickHouse](https://github.com/ClickHouse/ClickHouse). We appreciate the excellent work of the ClickHouse team.
+
+## Quick start
+
+### Start with TiDB Cloud
+
+Quickly explore TiFlash with [a free trial of TiDB Cloud](https://tidbcloud.com/signup).
+
+See [TiDB Cloud Quick Start Guide](https://docs.pingcap.com/tidbcloud/tidb-cloud-quickstart).
+
+### Start with TiDB
+
+See [Quick start with HTAP](https://docs.pingcap.com/tidb/stable/quick-start-with-htap) and [Use TiFlash](https://docs.pingcap.com/tidb/stable/use-tiflash).
 
 ## Build TiFlash