Don't escape plus not followed by a whitespace

[ocavue]

Initial checklist

• I read the support docs
• I read the contributing guide
• I agree to follow the code of conduct
• I searched issues and couldn’t find anything (or linked relevant results below)
• If applicable, I’ve added docs and tests

Description of changes

This PR improves the escape unsafe rule for +. If a + is not followed by [\ \t\r\n], then it won't turn into a list item, thus we don't need to escape it.

[ocavue]

Some issues about the CI:

1. There is a typing error. It seems that it's not caused by this PR. I added a @ts-expect-error.
2. The type coverage rate from the npm run test is lower than 100%. However I could not find the uncovered code in mdast-util-to-markdown/coverage/lcov-report/index.html, which shows 100%.

[wooorm]

type-coverage is not coverage, it’s something else.

I’ve updated the internal types for zwitch and TS 4.9: https://github.com/syntax-tree/mdast-util-to-markdown/commits/main.

[wooorm]

You can try and improve the - case with {atBreak: true, character: '-', after: '(?:[ \t\r\n\-])'}, and the * case with {atBreak: true, character: '*', after: '(?:[ \t\r\n\*])'}

[ocavue]

The CI is green after rebasing the latest main branch. Thanks for your helping.

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If I improve the - case and * case by adding after to these two rules, I cannot pass the test should prevent breaking out of code (-). It seems that inline-code.js is reusing these unsafe patterns to transform EOL into whitespace. I'm not sure what's the best way to fix it. Should I create a separate pattern list for inline-code.js (instead of reusing existed atBreak: true patterns in unsafe.js)?

[wooorm]

I'm not sure what's the best way to fix it

These test check for something that was being escaped, but did not strictly need to be escaped. See 2f3eeb7

[wooorm]

Released, thanks! https://github.com/syntax-tree/mdast-util-to-markdown/releases/tag/1.4.0