Create and deploy custom admonitions

## Feature description

Antora has [built-in admonitions](https://docs.antora.org/antora/latest/asciidoc/admonitions/). Change our repository's admonitions to the new styles.

## Examples (optional)

![Group 1](https://user-images.githubusercontent.com/372742/204928892-70a4ce11-7e1d-4204-bc95-66307a2c6ab8.png)

