v1.11.0 Improved Nested Callouts & Breakless lists

Resolves #7

Supports whitespaces after leading > symbols.

> [!info]
> > [!info]
> > > Blockquote

is now possible, previous syntax:

> [!info]
>> [!info]
>> > Blockquote

Also added a new option (enabled by default) to handle breakless lists

This shouldn't interfere with the previous syntax

# Before:
> [!info]
> Text here
>
> - list item
> - another list item

# After:
> [!info]
> Text here
> - list item
> - another list item

Disable the new behavior

This behavior shouldn't cause any issues, but can be disabled by setting breakless_lists to false in the mkdocs.yml configuration file

plugins:
  - search
  - callouts:
      breakless_lists: false