Support space in the markup of autoformat rules

[sepsol]

Description
I'm trying to achieve the results in the table below using autoformat but I'm only able to get the first one. If I put any spaces in my markup it breaks that rule altogether.

Status	Markup + Trigger	Result
✅	2* + 3	2×3
❌	2* + 3	2× 3
❌	2 * + 3	2 ×3
❌	2 * + 3	2 × 3

Steps

1. Go to the sandbox below
2. Follow the instruction on the page in yellow
3. Compare the result with what's expected in the code or with the table above here

Sandbox

https://codesandbox.io/s/plate-space-breaks-trigger-v6i2n?file=/src/App.js

Expectation
The expectation is for the marks to accept space characters, so that rules like the ones above could be implemented.

Environment

• slate: 0.63.0
• slate-react: 0.65.2
• browser: chrome