fix: 修正 logo 中 N 和 G 字母造型

N 添加对角线笔画（█▄ █），G 添加内横杠（█ ▀█），
避免与 O 字母造型雷同。同步更新 ui.ts 中的硬编码 wordmark。

packages/docs/essentials/code.mdx

@@ -0,0 +1,35 @@
+---
+title: "Code blocks"
+description: "Display inline code and code blocks"
+icon: "code"
+---
+
+## Inline code
+
+To denote a `word` or `phrase` as code, enclose it in backticks (`).
+
+```
+To denote a `word` or `phrase` as code, enclose it in backticks (`).
+```
+
+## Code blocks
+
+Use [fenced code blocks](https://www.markdownguide.org/extended-syntax/#fenced-code-blocks) by enclosing code in three backticks and follow the leading ticks with the programming language of your snippet to get syntax highlighting. Optionally, you can also write the name of your code after the programming language.
+
+```java HelloWorld.java
+class HelloWorld {
+    public static void main(String[] args) {
+        System.out.println("Hello, World!");
+    }
+}
+```
+
+````md
+```java HelloWorld.java
+class HelloWorld {
+    public static void main(String[] args) {
+        System.out.println("Hello, World!");
+    }
+}
+```
+````