Adding a > to the beginning of a line forces a conversion to a Quote block

[mapk]

Describe the bug
I'm trying to create my own list of items and add my own bullet point, a > character. Every time I do this, Gutenberg converts the Paragraph block to a Quote block. If I was in some sort of markdown editor, I'd expect this, but I'm not. I'm just trying to add a > to the beginning of my paragraph.

To reproduce
Steps to reproduce the behavior:

1. Add a Paragraph block.
2. Add a > character to the beginning of the text.
3. Add a space after that character.
4. Observe the block switch to a Quote block.

Expected behavior
I expect to add any character I want anywhere on the page without triggering a markdown switch of blocks.

Screenshots

Desktop (please complete the following information):

• OSX
• Firefox 68.0
• Gutenberg 6.1

[ellatrix]

There’s a PR to make it easier to undo such transforms: #14776. Would that help?

[ellatrix]

We have the same thing for lists (* ), separators (---), and code formatting `code`.