Some AsciiDoc blocks are not rendered

Summary

Several AsciiDoc blocks are not rendered (either correctly or at all), although being formally documented in GitLab docs.

Specifically, blocks of type -

• open
• example
• sidebar

Example Project Document

AsciiDoc file: https://gitlab.com/itayk-private/learn-gitlab/-/snippets/2321418

e.g. (snippet of above file):

****
sidebar - auxiliary content that can be read independently of the main content
****

What is the current bug behavior?

The open, example, sidebar block are not rendered as expected; Other types of AsciiDoc blocks do render correctly.

See output of the documentation's examples:

What is the expected correct behavior?

As specified in GitLab's docs:

https://docs.gitlab.com/ee/user/asciidoc.html#blocks

Implementation proposal

We can add missing classes to the list first.

div: ALIGNMENT_BUILTINS_CLASSES + ['openblock', 'exampleblock', 'sidebarblock', 'admonitionblock'].freeze,

link to file

After that, we can define CSS styles for them to highlight these blocks.