chore: change default language of README

Author: CoderSerio

README.md

@@ -1,22 +1,30 @@
 # Nighta
 
-language: [中文](./README_CN.md) | [ENGLISH](.)
+语言: [中文](.) | [ENGLISH](./README_EN.md)
 
-`Nighta` is a lightweight scripting language, with its name signifying "something created overnight."
+<div style="text-align: center;">
+  <img 
+    alt="Nighta" 
+    src="./doc/public/nighta.png" 
+    style="width: 240px; border-radius: 50%; overflow: hidden;"
+  >
+</div>
 
-## Code Sample
+`Nighta` 是一款轻量级的脚本语言。其名字的寓意是“一夜之间产生的事物”。
+
+## 代码示例
 
 ```nighta
   (var msg1 "Hello,")
   (var msg2 "World!")
-  (say (+ msg1 msg2))
+  (say (msg1 + msg2))
 ```
 
-## Quick Start
-- TODO: Coming Soon...
+## 快速开始
+现阶段，我们可以在 [Playground](https://coderserio.github.io/Nighta/#/playground/) 中使用 Nighta 进行编程。
 
-## Documentation
-Our comprehensive official documentation is under active development and expansion.
+## 文档
+阅读 [文档](https://coderserio.github.io/Nighta/#/) 获取更多关于 Nighta 的细节！
 
-## Contribution Guide
-Eager to contribute to Nighta's growth? It might not be the time just yet...
+## 贡献指南
+想要为Nighta的发展添砖加瓦？这或许还不到时候...

README_CN.md

@@ -0,0 +1,30 @@
+# Nighta
+
+language: [中文](./README.md) | [ENGLISH](.)
+
+<div style="text-align: center;">
+  <img 
+    alt="Nighta" 
+    src="./doc/public/nighta.png" 
+    style="width: 240px; border-radius: 50%; overflow: hidden;"
+  >
+</div>
+
+`Nighta` is a lightweight scripting language, with its name signifying "something created overnight."
+
+## Code Sample
+
+```nighta
+  (var msg1 "Hello,")
+  (var msg2 "World!")
+  (say (msg1 + msg2))
+```
+
+## Quick Start
+Currently, we can code with Nighta in the [Playground](https://coderserio.github.io/Nighta/#/playground/)
+
+## Document
+Read [Document](https://coderserio.github.io/Nighta/#/) to learn about Nighta more!
+
+## Contribution Guide
+Eager to contribute to Nighta's growth? It might not be the time just yet...