docs(readme): update readme

README.md

@@ -15,7 +15,7 @@ English | [简体中文](./README-CN.md) | [日本語](./README-JP.md)
 
 [MQTT X](https://mqttx.app) is a cross-platform MQTT 5.0 client tool open sourced by [EMQ](https://www.emqx.com/en), which can run on macOS, Linux and Windows, and supports formatting MQTT payload.
 
-[MQTT X](https://mqttx.app) simplifies the operation logic of the page with the help of chatting software, makes it easy and quick to create multiple simultaneous online MQTT client connections, test the connection, publish, and subscribe functions of MQTT/TCP, MQTT/TLS, MQTT/WebSocket as well as other MQTT protocol features.
+[MQTT X](https://mqttx.app) simplifies test operation with the help of a familiar, chat-like interface. It’s easy and quick to create multiple, simultaneous online MQTT client connections, and can test the connection, publishing, and subscription functions of MQTT/TCP, MQTT/TLS, MQTT/WebSocket as well as other MQTT protocol features.
 
 > [MQTT](http://mqtt.org/faq) stands for MQ Telemetry Transport. It is a publish/subscribe, extremely simple and lightweight messaging protocol, designed for constrained devices and low-bandwidth, high-latency or unreliable networks.
 

docs/manual.md

@@ -357,7 +357,9 @@ MQTT X is an open source cross-platform MQTT desktop client tool. It can be used
 
 **Q: Why does MQTT X use the UI design of chat software?**
 
-Based on the understanding of the MQTT protocol of pub/sub model, MQTT X simplifies the operation logic of the page with the help of chatting software. For example, create a new connection as a User A, subscribe to a Topic, just like to join a chat channel, and then create a new connection as a User B, publish a message to the Topic that User A has subscribed to, we can receive the message from User B in User A's page. In fact, in the IoT world as well, devices can use pub/sub feature of MQTT to communicate with each other. MQTT X emulates this and translates it into the user interface to help users understand and test MQTT-related content faster.
+Based on the understanding of the MQTT protocol of pub/sub model. It simplifies test operation with the help of a familiar, chat-like interface. It’s easy and quick to create multiple, simultaneous online MQTT client connections, and can test the connection, publishing, and subscription functions of MQTT/TCP, MQTT/TLS, MQTT/WebSocket as well as other MQTT protocol features.
+
+For example, create a new connection as a User A, subscribe to a Topic, just like to join a chat channel, and then create a new connection as a User B, publish a message to the Topic that User A has subscribed to, we can receive the message from User B in User A's page. In fact, in the IoT world as well, devices can use pub/sub feature of MQTT to communicate with each other. MQTT X emulates this and translates it into the user interface to help users understand and test MQTT-related content faster.
 
 **Q: Is MQTT X free?**