[ISSUE #3949] Add README

docs/en/README.md

@@ -33,8 +33,8 @@
 
 - [Cluster Deployment](dledger/deploy_guide.md)：introduce how to deploy Dledger in cluster.
 
-- [GRPC Proxy Deployment](proxy/deploy_guide.md)
-Introduce how to deploy gRPC proxy (both `Local` mode and `Cluster` mode).
+- [Proxy Deployment](proxy/deploy_guide.md)
+  Introduce how to deploy proxy (both `Local` mode and `Cluster` mode).
 
 ### 5. Operation and maintenance management
 - [Operation](operation.md)：introduce RocketMQ's deployment modes that including single-master mode, multi-master mode, multi-master multi-slave mode and so on, as well as the usage of operation tool mqadmin.

docs/en/proxy/deploy_guide.md

@@ -1,32 +1,37 @@
 # RocketMQ Proxy Deployment Guide
 
 ## Overview
-RocketMQ Proxy supports two deployment modes, `Local` mode and `Cluster` mode. 
 
-With `Local` mode, `Proxy` deployed with `Broker` in the same process with inter-process communication.
-
-While `Cluster` mode, `Proxy` is a single cluster who communicate `Broker` with remote procedure call. In this way, `Proxy` acts as a stateless computing components while `Broker` is a stateful components with local storage. This form of deployment makes RocketMQ an architecture of separation of computing and storage.
+RocketMQ Proxy supports two deployment modes, `Local` mode and `Cluster` mode.
 
 ## Configuration
-The configuration applies to both the `Cluster` mode and `Local` mode, whose default path is distribution/conf/rmq-proxy.json directory. 
+
+The configuration applies to both the `Cluster` mode and `Local` mode, whose default path is
+distribution/conf/rmq-proxy.json directory.
 
 ## `Cluster` mode
+
 * Set configuration field `nameSrvAddr`.
 * Set configuration field `proxyMode` to `cluster` (case insensitive).
 
-
 Run the command below.
+
 ```shell
 nohup sh mqproxy &
 ```
+
 The command will only run `Proxy` itself. It requires `Namesrv` and `Broker` components running.
 
 ## `Local` mode
+
 * Set configuration field `nameSrvAddr`.
 * Set configuration field `proxyMode` to `local` (case insensitive).
 
 Run the command below.
+
 ```shell
 nohup sh mqproxy &
 ```
-The command will not only run `Proxy`, but also run `Broker`. It requires `Namesrv` only and there's no need for extra `Broker`.
+
+The command will not only run `Proxy`, but also run `Broker`. It requires `Namesrv` only and there's no need for
+extra `Broker`.

proxy/README.md

@@ -0,0 +1,59 @@
+rocketmq-proxy
+--------
+
+## Introduction
+
+`RocketMQ Proxy` is a stateless component that makes full use of the newly introduced `pop` consumption mechanism to
+achieve stateless consumption behavior. `gRPC` protocol is supported now and all the message types including `normal`
+, `fifo`, `transaction` and `delay` are supported via `pop`. `Proxy` will translate incoming traffic into
+customized `Remoting` protocol to access `Broker` or `Namesrv`.
+
+`Proxy` also handles SSL, authorization/authentication and logging/tracing/metrics and is in charge of connection
+management and traffic governance.
+
+### Multi-language support.
+
+`gRPC` combined with `Protocol Buffer` makes it easy to implement clients with both `java` and other programming
+languages. See [rocketmq-clients](https://github.com/apache/rocketmq-clients) for more information.
+
+### Multi-protocol support.
+
+With `Proxy` as a traffic interface, it's convenient to implement multiple protocols upon proxy. `gRPC` protocol is
+implemented first and the customized `Remoting` protocol will be implemented later. HTTP/1.1 will also be taken into
+consideration.
+
+## Architecture
+
+`RocketMQ Proxy` has two deployment modes: `Cluster` mode and `Local` mode. With both modes, `Pop` mode is natively supported
+in `Proxy`.
+
+### `Cluster` mode
+
+While in `Cluster` mode, `Proxy` is an independent cluster that communicates with `Broker` with remote procedure call. In
+this scenario, `Proxy` acts as a stateless computing component while `Broker` is a stateful component with local
+storage. This form of deployment introduces the architecture of separation of computing and storage for RocketMQ.
+
+Due to the separation of computing and storage, `RocketMQ Proxy` can be scaled out indefinitely in `Cluster` mode to
+handle traffic peak while `Broker` can focus on storage engine and high availability.
+
+![](../docs/en/images/rocketmq_proxy_cluster_mode.png)
+
+### `Local` mode
+
+`Proxy` in `Local` mode has more similarity with `RocketMQ` 4.x version, which is easily deployed or upgraded for
+current RocketMQ users. With `Local` mode, `Proxy` deployed with `Broker` in the same process with inter-process
+communication so the network overhead is reduced compared to `Cluster` mode.
+
+![](../docs/en/images/rocketmq_proxy_local_mode.png)
+
+## Deploy guide
+
+See [Proxy Deployment](../docs/en/proxy/deploy_guide.md)
+
+## Related
+
+* [rocketmq-apis](https://github.com/apache/rocketmq-apis): Common communication protocol between server and client.
+* [rocketmq-clients](https://github.com/apache/rocketmq-clients): Collection of Polyglot Clients for Apache RocketMQ.
+* [RIP-37: New and Unified APIs](https://shimo.im/docs/m5kv92OeRRU8olqX): RocketMQ proposal of new and unified APIs
+  crossing different languages.
+* [RIP-39: Support gRPC protocol](https://shimo.im/docs/gXqmeEPYgdUw5bqo): RocketMQ proposal of gRPC protocol support.