[Feature Request] Markdown alert support

[lrockreal]

I have checked the following:

• [X] I've searched existing issues and found nothing related to my issue.

Describe the feature you want to add

Alerts are an extension of Markdown used to emphasize critical information. While "fake" versions of these alerts can be created using blockquotes, supporting them natively would allow for richer documentation.

Mockups or Images of the feature

Github renders these alerts in the following way:

[!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.

In markdown:

> [!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.