feat: support GFM alerts & render perf

[dribble-njr]

• support GFM alerts
• indent code block render abnomal (mac style or not both)
• ensure proper Markdown parsing for link

before:

after:

[github-actions]

🎊 PR Preview has been successfully built and deployed to https://doocs-md-preview-pr-446.surge.sh

[YangFong]

Need to check preview:

[yanglbme]

是的，无法正常预览

[dribble-njr]

ok，我排查一下

[dribble-njr]

已修复

[YangFong]

测试数据：

> [!NOTE]  
> Highlights information that users should take into account, even when skimming.

> [!TIP]
> Optional information to help a user be more successful.

> [!IMPORTANT]  
> Crucial information necessary for users to succeed.

> [!WARNING]  
> Critical content demanding immediate user attention due to potential risks.

> [!CAUTION]
> Negative potential consequences of an action.

编辑器可以正常保存并浏览，就是使用比较费劲，必须要全部大写，

在暗色模式下，会有所不搭：

这是在微信浏览中的默认表现，可以做一下暗色预览适配：

[dribble-njr]

应该可以了，增加了预览的深色模式适配 & 大小写匹配

[yanglbme]

全大写的情况下，渲染后的文本多了 [!IMPORTANT]

[dribble-njr]

抱歉，漏改一个地方

[yanglbme]

Caution 我看着不太对

[yanglbme]

看着没啥问题了，准备合并，感谢你的贡献 @dribble-njr

[dribble-njr]

稍等，我准备再做一点优化， @yanglbme 自定义 GFM 样式那块之前的写法有点小问题

[yanglbme]

好

[dribble-njr]

麻烦再看看，这次修复了之前 GFM 块不随字体样式改变的问题，并且优化了他的自定义样式

[yanglbme]

可以