Fix(DecorationNode): improve Inefficient regular expression

[progfay]

Proposed Changes

• Regular Expression Denial-of-Service Attack flaw has found by CodeQL
  • https://github.com/progfay/scrapbox-parser/security/code-scanning/1?query=ref%3Arefs%2Fpull%2F518%2Fhead

PoC

const decorationRegExp = /\[[!"#%&'()*+,-./{|}<>_~]+ (?:\[[^\]]+\]|[^\]])+\]/
`[! ${'['.repeat(30000)}z`.match(decorationRegExp) // ReDoS!!!

Changes

- const decorationRegExp = /\[[!"#%&'()*+,-./{|}<>_~]+ (?:\[[^\]]+\]|[^\]])+\]/
+ const decorationRegExp = /\[[!"#%&'()*+,-./{|}<>_~]+ (?:\[[^[\]]+\]|[^\]])+\]/

/\[[^[\]]+\]/ RegExp fail matching for [[ with no back tracking.