Incorrect indentation for lists and quotes when using the richtext example.

[slightknack]

Description and Recording
This looks like a cool project — opening an issue because I'm hoping to help it improve.

Using the example editor: https://www.slatejs.org/examples/richtext.
Was messing around and got a bullet point without any indentation:

Also got a quote stuck at the front of the list with additional indentation:

Not 100% sure why this is indented, is it a feature?

Here's another gif showing general unexpected behavior:

Although the second item is highlighted, clicking turn this into a bulleted list, etc affects the unrelated 4th element.

Steps
Again, not entirely sure, but here's what I did. To reproduce the behavior:

1. Go to 'https://www.slatejs.org/examples/richtext'
2. Delete the default example
3. Make a list
4. Highlight different portions and enter different text, trying to switch types using the menu
5. Something should break?

I apologize for not being more specific. I was just messing around and don't remember the exact steps, and don't really have enough time to take a deep dive to determine what the heart of the issue is. Sorry for not being of more help.

Expectation
Switching the type of element should not invoke any hidden state that is opaque to the end user. If I highlight the second element to make it a bulleted list, it should be a bulleted list.

Environment

• Slate Version: Latest as of today used on the website I linked. Probs 0.59 or something.
• Operating System: MacOS Big Sur, Intel
• Browser: Firefox 90.0.2

Context
Wanted to give it a try, but ran into some basic issues while messing around.

[dylans]

I believe this will be fixed as a result of the fix in #4489 though it requires verification.

[slightknack]

I no longer have the hardware on which I originally produced the issue, and haven't been able to reproduce it on this machine. Unless something similar pops up in the future, I'll close this issue for now. Thanks for your work on this project!