feat(nng-mqtt): add README.md in English

Author: alvin1221

mqtt-client-C-nng/README.md

@@ -1,32 +1,34 @@
 # NanoSDK
 
-### 安装NanoSDK库
+> [中文](./README_ZH.md)
+
+### Install NanoSDK library
 
 ```shell
 git clone https://github.com/emqx/NanoSDK
 cd NanoSDK
 mkdir build 
 cd build
 cmake -G Ninja ..
-# 编译TLS: 
+# Build with TLS: 
 # cmake -G Ninja -DNNG_ENABLE_TLS=ON ..
-# 编译SQLITE: 
+# Build with SQLITE: 
 # cmake -G Ninja -DNNG_ENABLE_SQLITE=ON ..
 ninja
 ninja install
 ```
 
-### 创建nng_socket
+### Open and create nng_socket
 
 ```c
 nng_socket sock;
 nng_mqtt_client_open(&sock);
 nng_mqttv5_client_open(&sock);
 ```
 
-### 创建work
+### Create work
 
-#### work定义
+#### work struct
 
 ```c
 struct work {
@@ -37,7 +39,7 @@ struct work {
 };
 ```
 
-#### 为socket创建n个work
+#### Create works for socket
 
 ```c
 static size_t nwork = 32;
@@ -49,7 +51,7 @@ for (i = 0; i < nwork; i++) {
 }
 ```
 
-### 创建并设置mqtt connect消息体
+#### Initialize connect message
 
 ```c
 nng_msg *msg;
@@ -58,16 +60,15 @@ nng_mqtt_msg_set_packet_type(msg, NNG_MQTT_CONNECT);
 nng_mqtt_msg_set_connect_keep_alive(msg, 60);
 nng_mqtt_msg_set_connect_clean_session(msg, true);
 nng_mqtt_msg_set_connect_proto_version(msg, opts->version);
- nng_mqtt_msg_set_connect_user_name(msg, "admin");
- nng_mqtt_msg_set_connect_password(msg, "public");
+nng_mqtt_msg_set_connect_user_name(msg, "admin");
+nng_mqtt_msg_set_connect_password(msg, "public");
 ```
 
 
 
-### 创建并设置nng_dialer
+### Initialize nng_dialer
 
 ```c
-
 nng_mqtt_set_connect_cb(sock, connect_cb, &sock);
 nng_mqtt_set_disconnect_cb(sock, disconnect_cb, NULL);
 
@@ -88,15 +89,7 @@ nng_dialer_start(dialer, NNG_FLAG_NONBLOCK);
 ```
 
 
-### 状态机回调函数
-
-> 本实例演示从初始INIT状态进入到RECV状态后进入数据接收状态
->
-> RECV状态中获取收到的PUBLISH数据
->
-> WAIT状态中进行清理nng_msg并重用，组装一个PUBLISH消息，设置SEND状态并进入发送回调
->
-> SEND状态获取发送结果，并返回到RECV状态中
+### State callback function
 
 ```c
 void
@@ -179,7 +172,8 @@ client_cb(void *arg)
 }
 ```
 
-### 启动回调函数
+### Start callback function
+
 ```c
 for (i = 0; i < nwork; i++) {
     client_cb(works[i]);
@@ -190,14 +184,15 @@ for (;;) {
 }
 ```
 
-### 工程编译及运行
+### Building and Running
+
 ```shell
 mkdir build
 cd build
 cmake -G Ninja ..
-# 编译TLS: 
+# Build with TLS: 
 # cmake -G Ninja -DNNG_ENABLE_TLS=ON ..
-# 编译SQLITE: 
+# Build with SQLITE: 
 # cmake -G Ninja -DNNG_ENABLE_SQLITE=ON ..
 ninja
 ```
@@ -211,6 +206,8 @@ mqtt_async:
                     [default: mqtt-tcp://127.0.0.1:1883]
     -n, --parallel  <number of works> (default: 32)
     -v, --version   <mqtt version> (default: 4)
+    -u, --username  <username>
+    -P, --password  <password>
     --sqlite        enable sqlite cache (default: false)
     -s, --secure    enable ssl/tls mode (default: disable)
     --cacert        <cafile path>
@@ -229,14 +226,16 @@ mqtt_async:
 ./mqtt_async --url "tls+mqtt-tcp://127.0.0.1:8883" -s --cacert ca.crt --cert server.crt --key server.key 
 ```
 
-### NanoSDK实现案例
+### NanoSDK Implementation case
+
 [nanomq_cli](https://github.com/emqx/nanomq/tree/master/nanomq_cli)
 
-### 完整代码工程
+### Project source
+
+[mqtt-client-C-nng](https://github.com/emqx/MQTT-Client-Examples/tree/master/mqtt-client-nng)
 
-[mqtt-client-nng](https://github.com/emqx/MQTT-Client-Examples/tree/master/mqtt-client-nng)
 
+### NanoSDK source
 
-### NanoSDK源码
 [NanoSDK](https://github.com/emqx/NanoSDK)