Markdown issues

[u9000-Nine]

Describe the bug

There are several issues with the current markdown parser:

• Unordered lists starting with - are interpreted as ordered lists.
• Escaped square brackets \[ aren't handled properly (interpreted as \\\[).
• Markdown is not interpreted at all inside blockquotes.
• Inline markdown (such as code, bold, italic, etc) inside link text prevents the link from being interpreted at all.
• Cannot create inline code inside a spoiler, but you can with the WYSIWYG editor.
• Cannot create nested lists.

Reproduction

Send a message with the following input:

- Foo
  - Bar
- Baz

[This is a link with a \[bracket\]](https://example.com)

[This is a link with `code`](https://example.com)

> #### The story of markdown
> 
> Markdown is a thing.

||`hidden code`||

Observe that it renders like this:

1. Foo
2. Bar
3. Baz

This is a link with a \[bracket\]

[This is a link with code](https://example.com)

#### The story of markdown

Markdown is a thing.

||hidden code||

Expected behavior

It should render as follows:

• Foo
  • Bar
• Baz

This is a link with a [bracket]

This is a link with code

The story of markdown

Markdown is a thing.

███████████

Versions info

Cinny version: v1.11.1

[u9000-Nine]

(See also fr: Multi-level / nested lists or code blocks should be supported · Issue #2469 · cinnyapp/cinny (Farside))