feat: disable single tilde strikethrough

[Exception0x0194]

Description

During the Markdown rendering process, content wrapped with two ~ characters is styled with a strikethrough - however, in LLM outputs (especially in role-playing scenarios), there are often many instances of ~ used as tonal markers. This results in cases where these tonal markers fail to display correctly, and instead, the text in between is rendered with a strikethrough. Additionally, when the LLM intends to strike through a paragraph, it mostly uses ~~ rather than a single ~. Therefore, we can remove the rendering rule for single ~ characters.

To address this, the remarkGfm plugin has been configured with the {singleTilde: false} parameter, ensuring that content wrapped with a single ~ is no longer styled with a strikethrough (while content wrapped with ~~ continues to render correctly).

Additional Notes

• Content wrapped with a single ~ is no longer styled with a strikethrough:
  喵呜~♡这就为您呈上暗夜女王的馈赠呦~ → 喵呜~♡这就为您呈上暗夜女王的馈赠呦~
• Content wrapped with ~~ is still rendered with a strikethrough:
  喵呜~~♡这就为您呈上暗夜女王的馈赠呦~~ → 喵呜~~♡这就为您呈上暗夜女王的馈赠呦~~

Screenshots

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[XiaoBuHaly]

这会导致所有一个波浪符号的删除线渲染错误，用户通常不会主动要求LLM在正常输出中使用何种形式创建删除线，因此仅仅禁用它是片面的。

建议：

1. （治标不治本）要求LLM使用全角括号
2. 新增对话设置中调整md渲染的开关，单独调整每个对话窗口，将设置中原有的md开关调整为对话默认设置